EX-4.1



 Exhibit 4.1 

Execution Version 
  

 
  

ONEOK, INC. 
 as Issuer;

 ONEOK PARTNERS, L.P. 

and 
 ONEOK PARTNERS
INTERMEDIATE LIMITED PARTNERSHIP 
 as Guarantors; 

and 
 U.S. BANK NATIONAL
ASSOCIATION 
 as Trustee 

SIXTH SUPPLEMENTAL INDENTURE 

Dated as of July 2, 2018 

to 
 INDENTURE 

relating to Securities 

Dated as of January 26, 2012 

4.55% Notes due 2028 
  

 
  







 TABLE OF CONTENTS 

 

							
	 	  	 	  	Page	 
	 ARTICLE 1 Relation to Indenture; Definitions and Other Provisions of General
Application
	  	 	1	 
	 SECTION 1.01.
	  	 Relation to Indenture
	  	 	1	 
	 SECTION 1.02.
	  	 Definitions
	  	 	1	 
	 SECTION 1.03.
	  	 General References
	  	 	2	 
		
	 ARTICLE 2 The Series of Securities
	  	 	2	 
	 SECTION 2.01.
	  	 The Form and Title of the Securities
	  	 	2	 
	 SECTION 2.02.
	  	 Amount
	  	 	3	 
	 SECTION 2.03.
	  	 Stated Maturity
	  	 	3	 
	 SECTION 2.04.
	  	 Interest and Interest Rates
	  	 	3	 
	 SECTION 2.05.
	  	 Optional Redemption
	  	 	3	 
	 SECTION 2.06.
	  	 Global Securities
	  	 	3	 
		
	 ARTICLE 3 Agreement to Guarantee
	  	 	3	 
	 SECTION 3.01.
	  	 Unconditional Guarantee
	  	 	3	 
	 SECTION 3.02.
	  	 Limitation on Guarantor Liability
	  	 	5	 
	 SECTION 3.03.
	  	 No Requirement to Endorse Notation of Guarantee
	  	 	6	 
	 SECTION 3.04.
	  	 Release of Guarantee
	  	 	6	 
	 SECTION 3.05.
	  	 Benefits Acknowledged
	  	 	6	 
		
	 ARTICLE 4 Miscellaneous
	  	 	6	 
	 SECTION 4.01.
	  	 Notices
	  	 	6	 
	 SECTION 4.02.
	  	 No Recourse Against Others
	  	 	6	 
	 SECTION 4.03.
	  	 Certain Trustee Matters.
	  	 	6	 
	 SECTION 4.04.
	  	 Continued Effect
	  	 	7	 
	 SECTION 4.05.
	  	 Governing Law
	  	 	7	 
	 SECTION 4.06.
	  	 Counterparts
	  	 	7	 

 EXHIBITS 
 Exhibit A: Form
of Note 







 SIXTH SUPPLEMENTAL INDENTURE, dated as of July 2, 2018 (this “Supplemental
Indenture”), among ONEOK, INC., an Oklahoma corporation (the “Company”), ONEOK PARTNERS, L.P., a Delaware limited partnership, and ONEOK PARTNERS INTERMEDIATE LIMITED
PARTNERSHIP, a Delaware limited partnership (each a “Guarantor” and together, the “Guarantors”), and U.S. BANK NATIONAL
ASSOCIATION, as trustee under the Indenture referred to below (in such capacity, the “Trustee”). 

RECITALS OF THE COMPANY 

WHEREAS, the Company and the Trustee have heretofore entered into an Indenture, dated as of January 26, 2012 (the “Original
Indenture”) (the Original Indenture, as amended and supplemented from time to time, including without limitation pursuant to this Supplemental Indenture, being referred to herein as the “Indenture”); and 

WHEREAS, under the Original Indenture, a new series of Securities may at any time be established by the Board of Directors of the Company, in
accordance with the provisions of the Original Indenture, and the terms of such series may be established by an indenture supplemental to the Original Indenture; and 

WHEREAS, the Company proposes to create under the Indenture a new series of Securities; and 

WHEREAS, in connection with the issuance of the Notes (as herein defined), each of the Guarantors desires to become a guarantor of, and
provide a guarantee of, the Notes; and 
 WHEREAS, all acts and things necessary to make the Notes and Guarantees (as herein defined), when
executed by the Company and the Guarantors, respectively, and when the Notes are authenticated and delivered by the Trustee as provided in the Original Indenture and this Supplemental Indenture, the valid and binding obligations of the Company and
the Guarantors, and to make this Supplemental Indenture a valid and binding agreement in accordance with the Original Indenture have been done or performed. 

NOW, THEREFORE, in consideration of the premises, agreements and obligations set forth herein and for other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, the parties hereto hereby agree, for the equal and proportionate benefit of all Holders of the Notes, as follows: 

ARTICLE 1 

RELATION TO INDENTURE; DEFINITIONS AND OTHER
PROVISIONS OF GENERAL APPLICATION 
 SECTION 1.01. Relation to
Indenture. 
 With respect to the Notes, this Supplemental Indenture constitutes an integral part of the Indenture. 

SECTION 1.02. Definitions. 

Except as may be provided in a future indenture supplemental to the Original Indenture, for the benefit of the Holders of the Notes but no
other series of Securities under the Indenture, whether now or hereafter issued and Outstanding, Article One of the Original Indenture shall be amended by adding the following defined terms to Section 101 in appropriate alphabetical sequence.
For all purposes of this Supplemental Indenture, capitalized terms used herein and not otherwise defined herein shall have the meanings assigned thereto in the Original Indenture. 







 “Adjusted Treasury Rate” means, with respect to any Redemption Date, the rate per annum
equal to the semi-annual equivalent yield to maturity of the Comparable Treasury Issue, assuming a price of the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for such Redemption
Date. 
 “Comparable Treasury Issue” means the U.S. Treasury security selected by the Quotation Agent as having a maturity
comparable to the remaining term of the Notes to be redeemed, assuming the Notes matured on April 15, 2028, that would be used, at the time of a selection and in accordance with customary financial practice, in pricing new issues of corporate
debt securities of comparable maturity to the remaining term of the Notes assuming the Notes matured on April 15, 2028. 

“Comparable Treasury Price” means, with respect to any Redemption Date, the Reference Treasury Dealer Quotation for such Redemption
Date. 
 “Quotation Agent” means a Reference Treasury Dealer. 

“Reference Treasury Dealer” means Citigroup Global Markets Inc., Merrill Lynch, Pierce, Fenner & Smith Incorporated, Mizuho
Securities USA LLC and Wells Fargo Securities, LLC and their respective successors; provided, however, that if any of the foregoing shall cease to be a primary U.S. Government Securities dealer in the United States (a
“Primary Treasury Dealer”), the Company shall substitute therefor another Primary Treasury Dealer and certify same to the Trustee. 

“Reference Treasury Dealer Quotation” means, with respect to any Redemption Date, the average, as determined by the Company and
certified to the Trustee by the Company, of the bid and asked prices for the Comparable Treasury Issue (expressed, in each case, as a percentage of its principal amount) quoted in writing to the Company by a Reference Treasury Dealer at 5:00 p.m. on
the third Business Day preceding such Redemption Date. 
 SECTION 1.03. General References. 

All references in this Supplemental Indenture to Articles and Sections, unless otherwise specified, refer to the corresponding Articles and
Sections of this Supplemental Indenture; and the terms “herein,” “hereof,” “hereunder” and any other word of similar import refers to this Supplemental Indenture. 

ARTICLE 2 

THE SERIES OF SECURITIES 

SECTION 2.01. The Form and Title of the Securities. 

There is hereby established a new series of Securities to be issued under the Indenture and to be designated as the Company’s 4.55% Notes
due 2028 (the “Notes”). The Notes shall be substantially in the form attached as Exhibit A hereto, in each case with such appropriate insertions, omissions, substitutions and other variations as are
required or permitted by the Indenture, and may have such letters, numbers or other marks of identification and such legends or endorsements placed thereon as the Company may deem appropriate or as may be required or appropriate to comply with any
laws or with any rules made pursuant thereto or with the rules of any securities exchange or automated quotation system on which the Notes may be listed or traded, or to conform to general usage, or as may, consistently with the Indenture, be
determined by the officers executing such Notes, as evidenced by their execution thereof. The Notes and any beneficial interest in the Notes shall be in minimum denominations of $2,000 and integral multiples of $1,000 in excess thereof. 

The Notes shall be executed, authenticated and delivered in accordance with the provisions of, and shall in all respects be subject to, the
terms, conditions and covenants of the Original Indenture as supplemented by this Supplemental Indenture (including the form of Note set forth as Exhibit A hereto (the terms of which are incorporated in and made a part of
this Supplemental Indenture for all intents and purposes)). 

  
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 SECTION 2.02. Amount. 

The aggregate principal amount of the Notes which may be authenticated and delivered pursuant hereto is unlimited. The Trustee shall initially
authenticate and deliver Notes for original issue in an initial aggregate principal amount of up to $800,000,000 upon delivery to the Trustee of a Company Order for the authentication and delivery of such Notes. The aggregate principal amount
of the Notes to be issued hereunder may be increased at any time hereafter and the series may be reopened for issuances of additional Notes upon Company Order without the consent of any Holder. The Notes issued on the date hereof and any such
additional Notes that may be issued hereafter shall be part of the same series of Securities for all purposes under the Indenture. 

SECTION 2.03. Stated Maturity. 

The Notes may be issued on any Business Day on or after July 2, 2018, and the Stated Maturity of the Notes shall be July 15, 2028.

 SECTION 2.04. Interest and Interest Rates.  

The rate or rates at which the Notes shall bear interest, the date or dates from which such interest shall accrue, the interest payment dates
on which any such interest shall be payable and the regular record date for any interest payable on any interest payment date, in each case, shall be as set forth in the form of Note set forth as Exhibit A hereto. 

SECTION 2.05. Optional Redemption. 

At its option, the Company may redeem the Notes, in whole or in part, in principal amounts of $2,000 and in integral multiples of $1,000 in
excess thereof, at any time or from time to time, at the applicable redemption price determined as set forth in the form of Note attached hereto as Exhibit A, in accordance with the terms set forth in the Notes and in accordance with Article
Eleven of the Original Indenture. 
 SECTION 2.06. Global Securities. 

The Notes shall initially be issuable in whole or in part in the form of one or more Global Securities. Such Global Securities (i) shall
be deposited with, or on behalf of, The Depository Trust Company, which shall act as Depositary with respect to the Notes, (ii) shall bear the legends applicable to Global Securities set forth in Section 204 of the Original Indenture,
(iii) may be exchanged in whole or in part for Notes in definitive form upon the terms and subject to the conditions provided in Section 304 of the Original Indenture and in this Supplemental Indenture and (iv) shall otherwise be
subject to the applicable provisions of the Indenture. 
 ARTICLE 3 

AGREEMENT TO GUARANTEE 

SECTION 3.01. Unconditional Guarantee.  

(a)    For value received, subject to Section 3.04 hereof, each of the Guarantors hereby fully, irrevocably,
unconditionally and absolutely guarantees to the Holders of the Notes and to the Trustee the due and punctual payment of the principal of, and premium, if any, and interest on such Notes, and all other amounts due and payable under the Indenture and
such Notes by the Company to the Trustee or such Holders (including, without limitation, all costs and expenses (including reasonable legal fees and 

  
 3 








 
disbursements of its agents and counsel) incurred by the Trustee or such Holders in connection with the enforcement of the Indenture and the Guarantees) (collectively, the “Indenture
Obligations”), when and as such amounts shall become due and payable, whether at the Stated Maturity, upon redemption or by declaration of acceleration or otherwise, according to the terms of such Notes and the Indenture. The guarantees
by the Guarantors set forth in this ARTICLE 3 are referred to herein as the “Guarantees.” Without limiting the generality of the foregoing, each Guarantor’s liability shall extend to all amounts that constitute part of
the Indenture Obligations and would be owed by the Company to the Trustee or such Holders under the Indenture and such Notes but for the fact that they are unenforceable, reduced, limited, impaired, suspended or not allowable due to the existence of
a bankruptcy, reorganization or similar proceeding involving the Company. 
 (b)    Failing payment when due of any
amount guaranteed pursuant to the Guarantees, for whatever reason, each Guarantor will be obligated (to the fullest extent permitted by applicable law) to pay the same immediately to the Trustee, without
set-off or counterclaim or other reduction whatsoever (whether for taxes, withholding or otherwise). The Guarantees hereunder are intended to be a general, unsecured, senior obligation of each Guarantor and
will rank pari passu in right of payment with all unsecured indebtedness of such Guarantor that is not, by its terms, expressly subordinated in right of payment to the Guarantees of such Guarantor. Each Guarantor hereby agrees that, to the
fullest extent permitted by applicable law, subject to Section 3.04 hereof, its obligations hereunder shall be full, irrevocable, unconditional and absolute, irrespective of the validity, regularity or enforceability of such Notes, the
Guarantees or the Indenture, the absence of any action to enforce the same, any waiver or consent by any such Holder with respect to any provisions hereof or thereof, the recovery of any judgment against the Company, any action to enforce the same
or any other circumstance which might otherwise constitute a legal or equitable discharge or defense of such Guarantor. Each Guarantor hereby agrees that in the event of a default in payment of any Indenture Obligations, whether at the Stated
Maturity, upon redemption or by declaration of acceleration or otherwise, legal proceedings may be instituted by the Trustee on behalf of such Holders or, subject to Section 507 of the Indenture, by such Holders, on the terms and conditions set
forth in the Indenture, directly against such Guarantor to enforce the Guarantees without first proceeding against the Company. 

(c)    To the fullest extent permitted by applicable law, subject to Section 3.04 hereof, the obligations of each
Guarantor under this ARTICLE 3 shall be as aforesaid full, irrevocable, unconditional and absolute and shall not be impaired, modified, discharged, released or limited by any occurrence or condition whatsoever, including, without limitation,
(i) any compromise, settlement, release, waiver, renewal, extension, indulgence or modification of, or any change in, any of the obligations and liabilities of the Company or either Guarantor contained in any of such Notes or the Indenture,
(ii) any impairment, modification, release or limitation of the liability of the Company, either Guarantor or any of their estates in bankruptcy, or any remedy for the enforcement thereof, resulting from the operation of any present or future
provision of any applicable Bankruptcy Law, as amended, or other statute or from the decision of any court, (iii) the assertion or exercise by the Trustee or any such Holder of any rights or remedies under any of such Notes or the Indenture or
their delay in or failure to assert or exercise any such rights or remedies, (iv) the assignment or the purported assignment of any property as security for any of such Notes, including all or any part of the rights of the Company or either
Guarantor under the Indenture, (v) the extension of the time for payment by the Company or either Guarantor of any payments or other sums or any part thereof owing or payable under any of the terms and provisions of any of such Notes or the
Indenture or of the time for performance by the Company or either Guarantor of any other obligations under or arising out of any such terms and provisions or the extension or the renewal of any thereof, (vi) the modification or amendment
(whether material or otherwise) of any duty, agreement or obligation of the Company or either Guarantor set forth in the Indenture, (vii) the voluntary or involuntary liquidation, dissolution, sale or other disposition of all or substantially
all of the assets, marshaling of assets and liabilities, receivership, insolvency, bankruptcy, assignment for the benefit of creditors, reorganization, arrangement, composition or readjustment, rehabilitation or relief of, or other similar
proceeding affecting, the Company or either Guarantor or any of their respective assets, or the disaffirmance of any 

  
 4 








 
of such Notes, the Guarantees or the Indenture in any such proceeding, (viii) the release or discharge of the Company or either Guarantor from the performance or observance of any agreement,
covenant, term or condition contained in any of such instruments by operation of law, (ix) the unenforceability of any of such Notes, the Guarantees or the Indenture, (x) any change in the name, business, capital structure, corporate
existence, or ownership of the Company or either Guarantor, or (xi) any other circumstance which might otherwise constitute a defense available to, or a legal or equitable discharge of, a surety or either Guarantor. 

(d)    To the fullest extent permitted by applicable law, each Guarantor hereby (i) waives diligence, presentment,
demand of payment, notice of acceptance, filing of claims with a court in the event of the merger, insolvency or bankruptcy of the Company or such Guarantor, and all demands and notices whatsoever, (ii) acknowledges that any agreement,
instrument or document evidencing the Guarantees may be transferred and that the benefit of its obligations hereunder shall extend to each holder of any agreement, instrument or document evidencing the Guarantees without notice to them and
(iii) covenants that its Guarantees will not be discharged except by complete performance of the Guarantees. To the fullest extent permitted by applicable law, each Guarantor further agrees that if at any time all or any part of any payment
theretofore applied by any Person to any Guarantees is, or must be, rescinded or returned for any reason whatsoever, including without limitation, the insolvency, bankruptcy or reorganization of either Guarantor, such Guarantees shall, to the extent
that such payment is or must be rescinded or returned, be deemed to have continued in existence notwithstanding such application, and the Guarantees shall continue to be effective or be reinstated, as the case may be, as though such application had
not been made. 
 (e)    Each Guarantor shall be subrogated to all rights of the Holders and the Trustee against the
Company in respect of any amounts paid by such Guarantor pursuant to the provisions of the Indenture; provided, however, that such Guarantor shall not be entitled to enforce or to receive any payments arising out of, or based upon,
such right of subrogation with respect to any of such Notes until all of such Notes and the Guarantees shall have been indefeasibly paid in full or discharged. 

(f)    To the fullest extent permitted by applicable law, no failure to exercise and no delay in exercising, on the part
of the Trustee or the Holders, any right, power, privilege or remedy under this ARTICLE 3 and the Guarantees shall operate as a waiver thereof, nor shall any single or partial exercise of any rights, power, privilege or remedy preclude any other or
further exercise thereof, or the exercise of any other rights, powers, privileges or remedies. The rights and remedies herein provided for are cumulative and not exclusive of any rights or remedies provided in law or equity. Nothing contained in
this ARTICLE 3 shall limit the right of the Trustee or the Holders to take any action to accelerate the maturity of such Notes pursuant to Article FIVE of the Indenture or to pursue any rights or remedies under the Indenture or under applicable law.

 SECTION 3.02. Limitation on Guarantor Liability. 

Each Guarantor and the Trustee hereby confirms that it is the intention of all such parties that the Guarantees of such Guarantor not
constitute a fraudulent transfer or conveyance for purposes of Bankruptcy Law, the Uniform Fraudulent Conveyance Act, the Uniform Fraudulent Transfer Act or any similar federal or state law to the extent applicable to any Guarantees. To effectuate
the foregoing intention, the Trustee and the Guarantors hereby irrevocably agree that the obligations of such Guarantor will be limited to the maximum amount that will, after giving effect to such maximum amount and all other contingent and fixed
liabilities of such Guarantor that are relevant under such laws, and after giving effect to any collections from, rights to receive contribution from or payments made by or on behalf of the other Guarantor in respect of the obligations of such other
Guarantor under this ARTICLE 3, result in the obligations of such Guarantor under its Guarantees not constituting a fraudulent transfer or conveyance. 

  
 5 








 SECTION 3.03. No Requirement to Endorse Notation of Guarantee.
 
 Each Guarantor hereby agrees that its execution and delivery of this Supplemental Indenture and the provisions set forth in this
ARTICLE 3 shall evidence its Guarantee without the need for notation on any Notes. 
 SECTION 3.04. Release of
Guarantee.  
 (a)    Notwithstanding anything to the contrary in this ARTICLE 3, if a Guarantor
(i) shall cease to be a subsidiary of the Company or (ii) shall no longer be (x) an obligor on, or issuer of, any capital markets debt securities or (y) a guarantor of any capital markets debt securities issued by the Company or
the other Guarantor, in each case other than the Notes, then, if no Default or Event of Default shall have occurred and be continuing, such Guarantor, upon giving notice to the Trustee to the foregoing effect, shall be deemed to be released from all
of its obligations under the Indenture, and the Guarantees shall be of no further force or effect with respect to such Guarantor. Following the receipt by the Trustee of any such notice, the Company shall cause the Indenture to be amended as
provided in Section 901 of the Indenture; provided, however, that the failure to so amend the Indenture shall not affect the validity of the termination of the Guarantees with respect to such Guarantor. 

(b)    In addition, upon (i) the exercise of the legal defeasance or covenant defeasance option or the satisfaction
and discharge of the Indenture as provided in ARTICLES FIFTEEN and FOUR, respectively, of the Indenture with respect to a series of Notes or (ii) a series of Notes ceasing to be Outstanding, each of the Guarantors shall be deemed to be released
from all its obligations under the Indenture with respect to such series of Notes and the Guarantees of such series of Notes shall be of no further force or effect. 

SECTION 3.05. Benefits Acknowledged. 

Each Guarantor acknowledges that it shall receive direct and indirect benefits from the financing arrangements contemplated by the Indenture
and from the Guarantees under this Supplemental Indenture. 
 ARTICLE 4 

MISCELLANEOUS 

SECTION 4.01. Notices. 

Notices to the Guarantor shall be made in accordance with Section 105 of the Indenture at the address for the Company set forth in such
Section. 
 SECTION 4.02. No Recourse Against Others. 

No director, officer, employee, partner (including, for greater certainty, any general partner of any general partnership who is an individual
person), incorporator, manager, stockholder or member of either Guarantor, as such, will have any liability for any obligations of the Company, such Guarantor or the other Guarantor under the Notes or the Indenture or for any claim based on, in
respect of, or by reason of, such obligations or their creation. The waiver and release are part of the consideration for the issuance of the Guarantees and the Notes. 

SECTION 4.03. Certain Trustee Matters.  

The recitals contained herein shall be taken as the statements of the Company and the Guarantors, and the Trustee assumes no responsibility for
their correctness. 

  
 6 








 The Trustee makes no representations as to the validity or sufficiency of this Supplemental
Indenture or the Notes or the proper authorization or the due execution hereof or thereof by the Company or any of the Guarantors. 
 Except
as expressly set forth herein, nothing in this Supplemental Indenture shall alter the duties, rights, privileges, immunities or obligations of the Trustee set forth in the Original Indenture, which shall be applicable in respect of the Notes and of
this Supplemental Indenture as fully and with like effect as if set forth herein in full. 
 The Trustee makes no representation or warranty
as to the validity or sufficiency of the information contained in the prospectus supplement related to the Notes, except such information which specifically pertains to the Trustee itself, or any information incorporated therein by reference with
respect to the Trustee. 
 SECTION 4.04. Continued Effect.  

Except as expressly supplemented and amended by this Supplemental Indenture, the Original Indenture shall continue in full force and effect in
accordance with the provisions thereof, and the Original Indenture (as supplemented and amended by this Supplemental Indenture) is in all respects hereby ratified and confirmed. This Supplemental Indenture and all its provisions shall be deemed a
part of the Original Indenture in the manner and to the extent herein and therein provided. 
 SECTION 4.05. Governing
Law.  
 This Supplemental Indenture and the Notes shall be governed by and construed in
accordance with the laws of the State of New York. This Supplemental Indenture and the Notes are subject to the provisions of the Trust Indenture Act that are required to be part of this Supplemental Indenture and the Notes and shall, to the extent
applicable, be governed by such provisions. 
 SECTION 4.06. Counterparts.  

This instrument may be executed in any number of counterparts, each of which, when delivered, shall be deemed to be an original, but all such
counterparts shall together constitute but one and the same instrument. 
 (Signature Pages Follow) 

  
 7 








 IN WITNESS WHEREOF, the parties hereto have caused this Supplemental Indenture to be duly
executed and delivered, all as of the day and year first above written. 
  

			
	ONEOK, INC.
		
	By:	 	 /s/ Terry K. Spencer

	Name:	 	Terry K. Spencer
	Title:	 	President and Chief Executive Officer
	
	 ONEOK PARTNERS, L.P.

		
	By:	 	ONEOK Partners GP, L.L.C.,
		 	its General Partner
		
	By:	 	 /s/ Walter S. Hulse III

	Name:	 	Walter S. Hulse III
	Title:	 	Chief Financial Officer and Executive Vice President, Strategic Planning and Corporate Affairs
	
	ONEOK PARTNERS INTERMEDIATE LIMITED PARTNERSHIP
		
	By:	 	 ONEOK ILP GP, L.L.C.,
 its General
Partner

		
	By:	 	 /s/ Walter S. Hulse III

	Name:	 	Walter S. Hulse III
	Title:	 	Chief Financial Officer and Executive Vice President, Strategic Planning and Corporate Affairs



  
 [Signature Page to Sixth
Supplemental Indenture] 









			
	 U.S. BANK NATIONAL ASSOCIATION,

as Trustee

		
	By:	 	 /s/ George Hogan

	Name:	 	George Hogan
	Title:	 	Vice President



  
 [Signature Page to Sixth
Supplemental Indenture] 








 EXHIBIT A 

[FORM OF FACE OF NOTE] 
 [If a Global
Security, insert—UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), NEW YORK, NEW YORK, TO THE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER,
EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO., OR TO SUCH OTHER ENTITY AS IS
REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.] 

[If a Global Security, insert—TRANSFERS OF THIS GLOBAL SECURITY SHALL BE LIMITED TO TRANSFERS IN WHOLE, BUT NOT IN PART, TO NOMINEES OF DTC OR TO A
SUCCESSOR THEREOF OR SUCH SUCCESSOR’S NOMINEE, AND TRANSFERS OF PORTIONS OF THIS GLOBAL SECURITY SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE RESTRICTIONS SET FORTH IN THE INDENTURE REFERRED TO HEREIN.] 

ONEOK, INC. 
 4.55% Note
due 2028 
  

					
	 No.    
	  	U.S.$
 	
            	 
 
		
	 CUSIP No. 682680 AU7
	  			

 ONEOK, Inc., an Oklahoma corporation (herein called the “Company”, which term includes any successor
Person under the Indenture hereinafter referred to), for value received, hereby promises to pay to                     , or registered assigns, the
principal sum of                      United States Dollars ($          ) on July 15, 2028, and to pay
interest thereon from July 2, 2018, or from the most recent interest payment date to which interest has been paid or duly provided for, semi-annually on January 15 and July 15 in each year, commencing on January 15, 2019, at the
rate of 4.55% per annum, until the principal hereof is paid or made available for payment and at the same rate per annum on any overdue principal and premium and on any overdue installment of interest. The amount of interest payable for any period
shall be computed on the basis of twelve 30-day months and a 360-day year. The amount of interest payable for any partial period shall be computed on the basis of a 360-day year of twelve 30-day months and the days elapsed in any partial month. In the event that any date on which interest is payable on this Note is not a Business Day,
then a payment of the interest payable on such date will be made on the next succeeding day which is a Business Day (and without any interest or other payment in respect of any such delay) with the same force and effect as if made on the date the
payment was originally payable. The interest so payable, and punctually paid or duly provided for, on any interest payment date will, as provided in such Indenture, be paid to the Person in whose name this Note (or one or more predecessor Notes) is
registered at the close of business on the regular record date for such interest, which record date shall be January 1 or July 1 (whether or not a Business Day), as the case may be, next preceding such interest payment date. Any such
interest not so punctually paid or duly provided for shall forthwith cease to be payable to the Holder on such regular record date and may either be paid to the Person in whose name this Note (or one or more predecessor Notes) is registered at the
close of business on a special record date for the payment of such Defaulted Interest to be fixed by the Trustee, notice of which shall be given to Holders of Notes not less than 10 days prior to such special record date, or be paid at any time in
any other lawful manner not inconsistent with the requirements of any securities exchange or automated quotation system on which the Notes may be listed or traded, and upon such notice as may be required by such exchange or automated quotation
system, all as more fully provided in the Indenture. 
 [If a Global Security, insert—Payment of the principal of (and premium, if any)
and any such interest on this Note will be made by transfer of immediately available funds to a bank account in the United States of America designated by the Holder to the Paying Agent in U.S. Dollars.] 







 [If a definitive Security, insert—Payment of the principal of (and premium, if any) and any
such interest on this Note will be made at the office or agency of the Company maintained for that purpose in U.S. Dollars or subject to any laws or regulations applicable thereto and to the right of the Company (as provided in the Indenture) to
rescind the designation of any such Paying Agent, at the offices of                     , and at such other offices or agencies as the Company may
designate, by U.S. Dollar check drawn on, or transfer to a U.S. Dollar account maintained by the payee with, a bank in The City of New York (so long as the applicable Paying Agent has received proper transfer instructions in writing at
least 10 days prior to the payment date); provided, however, that payment of interest may be made at the option of the Company by U.S. Dollar check mailed to the addresses of the Persons entitled thereto as such addresses shall appear in
the Security Register or by transfer to a U.S. Dollar account maintained by the payee with a bank in The City of New York (so long as the applicable Paying Agent has received proper transfer instructions in writing by the record date prior to
the applicable interest payment date).] 
 Reference is hereby made to the further provisions of this Note set forth on the reverse hereof,
which further provisions shall for all purposes have the same effect as if set forth at this place. 
 Unless the certificate of
authentication hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Note shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose. 







 IN WITNESS WHEREOF, the Company has caused this instrument to be duly executed. 

Dated:                    ,     
    
  

			
	ONEOK, INC.
		
	By:	 	
                     
                                         
                               

	Name:	 	
	Title:	 	


  

			
	ATTEST
		
	By:	 	
                     
                                         
       

	Name:	 	
	Title:	 	








 TRUSTEE’S CERTIFICATE OF AUTHENTICATION 

This is one of the Securities of the series designated therein referred to in the within-mentioned Indenture. 

Dated:            ,          

 

			
	 U.S. BANK NATIONAL ASSOCIATION,
 as
Trustee

		
	By:	 	  

		 	    Authorized Signatory








 [REVERSE OF NOTE] 

ONEOK, INC. 
 4.55% Note
due 2028 
 This security is one of a duly authorized issue of debt securities of the Company (the “Securities”), issued and
to be issued in one or more series under an Indenture, dated as of January 26, 2012, between the Company and U.S. Bank National Association, as Trustee (the “Trustee,” which term includes any successor trustee under the Indenture), as
amended and supplemented to date, including without limitation by the Sixth Supplemental Indenture thereto, dated July 2, 2018 among the Company, ONEOK Partners, L.P. and ONEOK Partners Intermediate Limited Partnership (each a
“Guarantor” and together, the “Guarantors”) and the Trustee, (such Indenture, as so amended and supplemented being referred to herein as the “Indenture”), to which Indenture and all indentures supplemental thereto
reference is hereby made for a statement of the respective rights, limitations of rights, obligations, duties and immunities thereunder of the Company, the Guarantors, the Trustee and the Holders of the Securities and of the terms upon which the
Securities are, and are to be, authenticated and delivered. This Security is one of the series designated on the face hereof. The Securities of this series are referred to herein as the “Notes.” 

On or after April 15, 2028 (three months prior to the maturity date of the Notes), the Notes will be subject to redemption at any time at
the option of the Company, in whole or in part, at a redemption price equal to 100% of the principal amount of the Notes to be redeemed, plus any accrued and unpaid interest thereon to the applicable Redemption Date (subject to the right of holders
of record on the relevant record date to receive interest due on an Interest Payment Date that is on or prior to the Redemption Date).

Prior to April 15, 2028 (three months prior to the maturity date of the Notes), the Notes will be subject to redemption at the option of
the Company, in whole or in part, at any time and from time to time, at a redemption price equal to the greater of (i) 100% of the principal amount of the Notes; or (ii) as determined by a Quotation Agent, the sum of the present values of the
remaining scheduled payments of principal and interest on the Notes to be redeemed that would be due if the Notes matured on April 15, 2028 (not including any portion of those payments of interest accrued as of the date of redemption)
discounted to the date of redemption on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Adjusted Treasury Rate plus 30 basis
points, plus, in the case of (i) and (ii), accrued but unpaid interest to the Redemption Date. 
 Unless the Company defaults in
payment of the redemption price, on and after the date of redemption, interest will cease to accrue on this Note or the portions hereof called for redemption. 

In the event of redemption of this Note in part only, a new Note or Notes of like tenor for the unredeemed portion hereof will be issued in
the name of the Holder hereof upon the cancellation hereof. 
 The Indenture contains provisions for defeasance at any time of (1) the
entire indebtedness of this Note or (2) certain restrictive covenants and Events of Default with respect to this Note, in each case upon compliance with certain conditions set forth in the Indenture. 

If an Event of Default with respect to the Notes shall occur and be continuing, the principal of the Notes may be declared due and payable in
the manner and with the effect provided in the Indenture. 
 The Guarantors fully, irrevocably, unconditionally and absolutely guarantee the
due and punctual payment of the principal of, and premium, if any, and interest on such Notes, and all other amounts due and payable under the Indenture and such Notes by the Company to the Trustee or such Holders. 

The Indenture permits, with certain exceptions as therein provided, the amendment thereof and the modification of the rights and obligations
of the Company, the Guarantors and the rights of the Holders of the Securities of each series to be affected under the Indenture at any time by the Company, the Guarantors and the Trustee with the consent of not less than the Holders of a majority
in principal amount of the Outstanding Securities of each series to be affected. The Indenture also contains provisions permitting the Holders of a majority in principal amount of the Outstanding Securities of each affected series, on behalf of the
Holders of all Securities of such series, to waive compliance by the Company and the Guarantors with certain provisions of the Indenture. The Indenture permits, with certain exceptions as therein provided, the Holders of a majority in principal
amount of 







 
Securities of any series then Outstanding to waive past defaults under the Indenture with respect to such series and their consequences. Any such consent or waiver by the Holder of this Note
shall be conclusive and binding upon such Holder and all holders of Notes of which this Note is a predecessor Note, whether or not notation of such consent or waiver is made upon this or any other Note. 

As provided in and subject to the provisions of the Indenture, the Holder of this Note shall not have the right to institute any action or
proceeding with respect to the Indenture or for the appointment of a receiver or trustee or for any other remedy thereunder, unless such Holder shall have previously given the Trustee written notice of a continuing Event of Default with respect to
the Notes, the Holders of not less than 25% in principal amount of the Notes at the time Outstanding shall have made written request to the Trustee to institute proceedings in respect of such Event of Default and offered the Trustee reasonable
indemnity against costs, expenses and liabilities to be incurred in compliance with such request and the Trustee shall not have received from the Holders of a majority in principal amount of Notes at the time Outstanding a direction inconsistent
with such request, and the Trustee shall have failed to institute any such proceeding for 60 days after receipt of such notice, request and offer of indemnity. The foregoing shall not apply to any suit instituted by the Holder of this Note for the
enforcement of any payment of principal hereof or any premium or interest hereon on or after the respective due dates expressed herein. 

No reference herein to the Indenture and no provision of this Note or of the Indenture shall alter or impair the obligation of the Company,
which is absolute and unconditional, to pay the principal of and any premium and interest on this Note at the times, place(s) and rate, and in the currency, herein prescribed. 

[If a Global Security, insert—This Global Security or portion hereof may not be exchanged for definitive Securities of this series except
in the limited circumstances provided in the Indenture. 
 The holders of beneficial interests in this Global Security will not be entitled
to receive physical delivery of definitive Securities except as described in the Indenture and will not be considered the Holders thereof for any purpose under the Indenture.] 

[If a definitive Security, insert—As provided in the Indenture and subject to certain limitations therein set forth, the transfer of this
Note is registerable in the Security Register, upon surrender of this Note for registration of transfer at the office or agency of the Company in The City of New York, or, subject to any laws or regulations applicable thereto and to the right of the
Company (limited as provided in the Indenture) to rescind the designation of any such transfer agent, at the offices of                      in the
Borough of Manhattan, The City of New York, and at such other offices or agencies as the Company may designate, duly endorsed by, or accompanied by a written instrument of transfer in form satisfactory to the Company and the Security Registrar duly
executed by, the Holder hereof or his attorney duly authorized in writing, and thereupon one or more new Notes of like tenor, of authorized denominations and for the same aggregate principal amount, will be issued to the designated transferee or
transferees.] 
 The Notes are issuable only in registered form without coupons in denominations of $2,000 and any whole multiple of $1,000
in excess thereof. As provided in the Indenture and subject to certain limitations therein set forth, Notes are exchangeable for a like aggregate principal amount of Notes and of like tenor of a different authorized denomination, as requested by the
Holder surrendering the same. 
 No service charge shall be made for any such registration of transfer or exchange, but the Company may
require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith. 
 Prior to due
presentment of this Note for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee may treat the Person in whose name this Note is registered as the owner hereof for all purposes, whether or not this Note is
overdue, and neither the Company, the Trustee nor any such agent shall be affected by notice to the contrary. 
 This Note shall be governed
by and construed in accordance with the laws of the State of New York. The Notes are subject to the provisions of the Trust Indenture Act that are required to be part of the Notes and shall, to the extent applicable, be governed by such provisions.

 All terms used in this Note which are defined in the Indenture shall have the meanings assigned to them in the Indenture. 







 [If a definitive Security, insert as a separate page— 

FOR VALUE RECEIVED, the undersigned hereby sell(s), assign(s) and transfer(s) unto
                                 (Please Print or Typewrite Name and Address of Assignee)
the within instrument of ONEOK, INC. and does hereby irrevocably constitute and appoint                      Attorney to transfer said instrument on
the books of the within-named Company, with full power of substitution in the premises. 
 Please Insert Social Security or 

Other Identifying Number of Assignee: 
  

							
	  
	 		  	  

				
	Dated:	 	  
	 		  	  

		 		 		  	(Signature)

  

			
	Signature Guarantee:	 	  

		 	 (Participant in a Recognized Signature

Guaranty Medallion Program)


 NOTICE: The signature to this assignment must correspond with the name as written upon the face of the within
instrument in every particular, without alteration or enlargement or any change whatever.] 







 [If a Global Security, insert as a separate page— 

SCHEDULE OF INCREASES OR DECREASES 

IN GLOBAL SECURITY 
 The
following increases or decreases in this Global Security have been made: 
  

									
	 Date of Exchange
	  	 Amount of

Decrease in

Principal

Amount of this

Global Security
	  	 Amount of

Increase in
Principal Amount

of this
 Global
Security
	  	 Principal Amount

of this Global

Security following

such decrease
 (or
increase)
	  	 Signature of
authorized officer

of Trustee or 

Depositary