SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 10-Q

[X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE 
	SECURITIES EXCHANGE ACT OF 1934 
	For the quarterly period ended September 30, 2005 or
( )   TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 (D) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from _______ to _______

Commission file number        333-104061-01

BCTC IV ASSIGNOR CORP.(Exact name of registrant as specified in its charter)



|Delaware                          | 04-3208532         
|--------------------------------- | -------------------
|(State or other jurisdiction      | (I.R.S. Employer   
|of incorporation or organization) | Identification No.)



One Boston Place, Suite 2100, Boston, Massachusetts  02108(Address of principal executive offices)           (Zip Code)

Registrants telephone number, including area code (617)624-8900Securities registered pursuant to Section 12(b) of the Act:



|Title of each class | Name of each exchangeon which registered
|------------------- | ----------------------------------------
|
|                    |                                         
|None                | None                                    

Securities registered pursuant to Section 12(g) of the Act:

Indicate by check mark whether the Fund (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities
Exchange Act of 1934 during the preceding twelve months (or for
such shorter period that the Fund was required to file such
reports), and (2) has been subject to such filing requirements for
the past 90 days.



|YES |  | NO | X
|--- |  | -- | -

Indicate by check mark whether the Fund is an accelarated filer (as defined in Rule 12b-2 of the Exchange Act).



|YES |  | NO | X
|--- |  | -- | -

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).





|YES | X | NO | 
|--- | - | -- | 



Indicate by check mark if disclosure of delinquent filers pursuant to 
Item 405 or Regulation S-K (229.405 of this chapter) is not contained 
herein, and will not be contained, to the best of registrant's knowledge, 
in definitive proxy or information statements incorporated by reference in 
Part III of this Form 10-Q or any amendment to this Form 10-Q.

__
|XX|

DOCUMENTS INCORPORATED BY REFERENCE

The following documents of the Fund are incorporated by reference:





|Form 10-Q    |                                                                             
|------------ | ----------------------------------------------------------------------------
|Parts        | Document                                                                    
|             |                                                                             
|Parts I, III | Form 10-K of BCTC IV Assignor Corp. dated December 31, 2004, as supplemented
|             |                                                                             
|             |                                                                             





BCTC IV ASSIGNOR CORP.

Form 10-Q QUARTERLY REPORT FOR THE PERIOD ENDED SEPTEMBER 30, 2005



TABLE OF CONTENTS



PART I



|Item 1. | Financial Statements                             
|------- | -------------------------------------------------
|Item 2. | Business                                         
|Item 3. | Management's Discussion and Analysis of Financial
|        | Condition and Results of Operations              
|Item 4. | Evaluation of Disclosure and Procedures          
|        |                                                  



PART II

|Item 6.    | Exhibits and Reports on Form 8-K
|---------- | --------------------------------
|           |                                 
|Signatures







PART I



BCTC IV Assignor Corp.



Balance Sheet





|                                  | September 30,
2005(Unaudited)                                                          | December 31,
2004(Audited)
|--------------------------------- | -------------------------------------------------------------------------------------- | --------------------------
|                                  |                                                                                        |                           
|ASSETS                           
|                                  |                                                                                        |                           
|INVESTMENTS IN OPERATING          |                                                                                        |                           
|                                  | PARTNERSHIPS (Note B)                                                                  | $    100                  
|                                  |                                                                                        |                           
|                                  | $100                                                                                   | $100                      
|                                  |                                                                                        |                           
|                                 
|LIABILITIES AND PARTNERS' DEFICIT
|                                  |                                                                                        |                           
|LIABILITIES                       |                                                                                        |                           
|                                  |                                                                                        |                           
|Subscription payable              | $100                                                                                   | $100                      
|                                  |                                                                                        |                           
|                                  | 100                                                                                    | 100                       
|                                  |                                                                                        |                           
|PARTNERS' DEFICIT                 |                                                                                        |                           
|                                  |                                                                                        |                           
|Limited Partners                  |                                                                                        |                           
|                                  | Common stock - 1,000 shares authorized, issued and outstanding, $1 par value per share | 1,000                     
|Less: subscription receivable     | (1,000)                                                                                | (1,000)                   
|                                  |                                                                                        |                           
|                                  | $100                                                                                   | $100                      
|                                  |                                                                                        |                           



NOTE A - ORGANIZATION



BCTC IV Assignor Corp. (the "Corporation") was organized on October 12, 1993 under the laws of the State of Delaware to act as the assignor limited partner of, and to acquire and hold a limited partnership interest in, Boston Capital Tax Credit Fund IV L.P. (the "Limited Partnership"). The Corporation will assign units of beneficial interest in its limited partnership interest to persons who purchase Beneficial Assignee Certificates (BACs), on the basis of one unit of beneficial interest for each BAC.  The Corporation will not have any interest in profits, losses or distributions on its own behalf.



NOTE B - INVESTMENT IN LIMITED PARTNERSHIP



On October 12, 1993, the Corporation was admitted as the assignor limited partner in Boston Capital Tax Credit Fund IV L.P. The Limited Partnership was formed to invest in real estate by acquiring, holding, and disposing of limited partnership interests in operating partnerships which will acquire, develop, rehabilitate, operate and own newly-constructed, existing or rehabilitated low-income apartment complexes.



|Item 2. | Management's Discussion and Analysis of Financial
|------- | -------------------------------------------------
|        | Condition and Results of Operations              

Business

BCTC IV Assignor Corp, a Delaware corporation(the "Assignor Limited Partner") was formed for the sole purpose of serving as an assignor for Boston Capital Tax Credit Fund IV L.P. (the "Fund") and will not engage in any other business. Units of beneficial interest in the Limited Partnership Interest of the Assignor Limited Partner will be assigned by the Assignor Limited Partner by means of beneficial assignee certificates ("BACs") to investors and investors will be entitled to all the rights and economic benefits of a Limited Partner of the Fund including rights to a percentage of the income, gains, losses, deductions, credits and distributions of the Fund.The Assignor Limited Partner is wholly-owned by John P. Manning.A Registration Statement on Form S-11 and the related prospectus, as supplemented (the "Prospectus") were filed with the Securities and Exchange Commission and became effective December 16, 1993 in connection with a public offering ("Offering") in one or more series of a minimum of 250,000 BACs and a maximum of 30,000,000 BACs at $10 per BAC.  On April 18, 1996 an amendment to Form S-11, which registered an additional 10,000,000 BACs for sale to the public in one or more series, became effective. On April 2, 1998 an amendment to Form S-11, which registered an additional 25,000,000 BACs for sale to the public in one or more series, became effective. On August 31, 1999 an amendment to Form S-11, which registered an additional 8,000,000 BACs for sale to the public became effective.  On July 26, 2000 an amendment to Form S-11, which registered an additional 7,500,000 BACs for sale to the public became effective. On July 23, 2001 an amendment to Form S-11, which registered an additional 7,000,000 BACs for sale to the public became effective.  On July 24, 2002 an amendment to Form S- 11, which registered an additional 7,000,000 BACs for sale to the public became effective.  On July 2, 2003, an amendment to Form S-11, which registered an additional 7,000,000 BACs for sale to the public became effective.  As of September 30, 2005, subscriptions had been received and accepted by the General Partner in Series 20, Series 21, Series 22, Series 23, Series 24, Series 25, Series 26, Series 27, Series 28, Series 29, Series 30, Series 31, Series 32, Series 33, Series 34, Series 35, Series 36, Series 37, Series 38, Series 39, Series 40, Series 41, Series 42, Series 43, Series 44, Series 45 and Series 46 for 83,651,080 BACs representing capital contributions of $836,537,885.
The Offering, including information regarding the issuance of BACs in series, is described on pages 144 to 149 of the Prospectus, as supplemented, under the caption "The Offering", which is incorporated herein by reference.

Description of Business

The Assignor Limited Partner's sole purpose is to act as a conduit through which all of the economic and tax benefits of an investment in the Fund are passed along to the investor BAC Holders.  The Assignor Limited Partner does not charge any fees for its services and has no income.The Fund's principal business is to invest as a limited partner in other limited partnerships (the "Operating Partnerships") each of which will own or lease and will operate an Apartment Complex exclusively or partially for low- and moderate-income tenants.  Each Operating Partnership in which the Fund will invest will own Apartment Complexes which are completed, newly-constructed, under construction or rehabilitation, or to-be constructed or rehabilitated, and which are expected to receive Government Assistance.  Each Apartment Complex is expected to qualify for the low-income housing tax credit under Section 42 of the Code (the "Federal Housing Tax Credit"), thereby providing tax benefits over a period of ten to twelve years in the form of tax credits which investors may use to offset income, subject to certain strict limitations, from other sources.  Certain Apartment Complexes may also qualify for the historic rehabilitation tax credit under Section 47 of the Code (the "Rehabilitation Tax Credit").  The Federal Housing Tax Credit and the Government Assistance programs are described on pages 64 to 88 of the Prospectus, as supplemented, under the captions "Tax Credit Programs" and "Government Assistance Programs," which is incorporated herein by reference.  Section 236 (f) (ii) of the National Housing Act, as amended, in Section 101 of the Housing and Urban Development Act of 1965, as amended, each provide for the making by HUD of rent supplement payments to low income tenants in properties which receive other forms of federal assistance such as Tax Credits.  The payments for each tenant, which are made directly to the owner of their property, generally are in such amounts as to enable the tenant to pay rent equal to 30% of the adjusted family income.  Some of the Apartment Complexes in which the Partnership has invested are receiving such rent supplements from HUD.  HUD has been in the process of converting rent supplement assistance to assistance paid not to the owner of the Apartment Complex, but directly to the individuals.  At this time, the Partnership is unable to predict whether Congress will continue rent supplement programs payable directly to owners of the Apartment Complex.  
As of September 30, 2005, the Fund had invested in 23 Operating Partnerships on behalf of Series 20, 14 Operating Partnership on behalf of Series 21, 29 Operating Partnerships on behalf of Series 22, 22 Operating Partnerships on behalf of Series 23, 24 Operating Partnerships on behalf of Series 24, 22 Operating Partnerships on behalf of Series 25, 45 Operating Partnerships on behalf of Series 26, 16 Operating Partnerships on behalf of Series 27, 26 Operating Partnerships on behalf of Series 28, 22 Operating Partnerships on behalf of Series 29, 20 Operating Partnerships on behalf of Series 30, 27 Operating Partnerships on behalf of Series 31, 17 Operating Partnerships on behalf of Series 32, 10 Operating Partnerships on behalf of Series 33, 14 Operating Partnerships on behalf of Series 34, 11 Operating Partnerships on behalf of Series 35, 11 Operating Partnerships on behalf of Series 36, 7 Operating Partnerships on behalf of Series 37, 10 Operating Partnerships on behalf of Series 38, 9 Operating Partnerships on behalf of Series 39, 16 Operating Partnerships on behalf of Series 40, 23 Operating Partnerships on behalf of Series 41, 22 Operating Partnerships on behalf of Series 42, 22 Operating Partnerships on behalf of Series 43, 9 Operating Partnerships on behalf of Series 44, 30 Operating Partnerships on behalf of Series 45 and 12 Operating Partnerships on behalf of Series 46.  A description of these Operating Partnerships is set forth in Item 2 herein.



|The business objectives of the Fund are to:
|-------------------------------------------
|(1)                                        
|(2)                                        
|(3)                                        
|(4)                                        



The business objectives and investment policies of the Fund are described more fully on pages 49 to 61 of the Prospectus, as supplemented, under the caption "Investment Objectives and Acquisition Policies," which is incorporated herein by reference.

The Assignor Limited Partner has no operational history and capital needs.



Employees

The Assignor Limited Partner does not have any employees and does not perform any services.

|Item 3 | Quantitative and Qualitative Disclosure About Market Risk
|------ | ---------------------------------------------------------
|       |                                                          
|       | Not Applicable                                           

|Item 4 | Controls & Procedures
|------ | ---------------------
|       |                      
|       | (a)                  
|       |                      
|       |                      
|       | (b)                  
|       |                      





PART II - OTHER INFORMATION



|Item 1. | Legal Proceedings                                          
|------- | -----------------------------------------------------------
|        |                                                            
|        | None                                                       
|        |                                                            
|Item 2. | Unregistered Sales of Equity Securities and Use of Proceeds
|        |                                                            
|        | None                                                       
|        |                                                            
|Item 3. | Defaults upon Senior Securities                            
|        |                                                            
|        | None                                                       
|        |                                                            
|Item 4. | Submission of Matters to a Vote of Security 
Holders       
|        |                                                            
|        | None                                                       
|        |                                                            
|Item 5. | Other Information                                          
|        |                                                            
|        | None                                                       
|        |                                                            
|Item 6. | Exhibits                                                   
|        |                                                            
|        | (a)Exhibits                                                
|        |                                                            
|        |                                                            
|        |                                                            
|        |                                                            
|        |                                                            
|        |                                                            
|        |                                                            
|        |                                                            
|        |                                                            







SIGNATURES

Pursuant to the requirements of Section 13 of the Securities Exchange
Act of 1934, the registrant has duly caused this Report to be signed on its behalf by the undersigned, thereunto duly authorized.

|                         |  | BCTC IV Assignor Corp.
|------------------------ |  | ----------------------
|                         |  |                       
|Date:  November 18, 2005 |  | By:                   
|                         |  |                       
|                         |  |                       

Pursuant to the requirements of the Securities Exchange Act of 1934,
this report has been signed below by the following persons on behalf of the
registrant and in the capacities and on the dates indicated:

|DATE:             | SIGNATURE:          | TITLE:                                                                   
|----------------- | ------------------- | -------------------------------------------------------------------------
|                  |                     |                                                                          
|November 18, 2005 | /s/ John P. Manning | Director, President (Principal Executive Officer), BCTC IV Assignor Corp.
|                  | John P. Manning    
|                  |                    
|                  |                    
|                  |                    



|DATE:             | SIGNATURE:       | TITLE:                                               
|----------------- | ---------------- | -----------------------------------------------------
|                  |                  |                                                      
|November 18, 2005 | /s/ Marc N. Teal | (Principal Financial Officer), BCTC IV Assignor Corp.
|                  | Marc N. Teal    
|                  |                 
|                  |                 
|                  |