EXHIBIT 10.31

GUARANTEE

THIS GUARANTEE (this "Guarantee"), dated as of February 26, 2003, by UbiquiTel Inc., a Delaware
corporation ("Parent") and parent company of UbiquiTel Operating Company ("Borrower"), and subsidiaries
of Borrower VIA Holding Inc., a California corporation, VIA Wireless LLC, a California limited liability company, and VIA Building, LLC, a Nevada limited liability company (collectively with
Parent, the "Guarantors"), is made in favor of the Purchasers of 14% Senior Unsecured Series B Notes of the Borrower pursuant to a Note Purchase
Agreement among Borrower, Parent and the Purchasers dated of even date herewith (the "Purchase Agreement"). All capitalized terms set forth herein and
not otherwise defined shall have the meanings as defined in the Purchase Agreement.

WITNESSETH:

WHEREAS, contemporaneously herewith on the date hereof, Borrower has executed and delivered to the Purchasers the Series B Notes;

WHEREAS,
pursuant to Section 10.8 of the Purchase Agreement, the Guarantors are required to execute and deliver to the Purchasers this Guarantee pursuant to which the Guarantors
shall jointly and severally unconditionally guarantee all of Borrower's Obligations (as defined below) under the Series B Notes on the terms and conditions set forth herein;

WHEREAS,
Borrower has agreed to make full and timely payments of principal, interest, penalties, fees, indemnifications, reimbursements, damages and other liabilities payable under the
Series B Notes and the Purchase Agreement (collectively, the "Obligations"); and

WHEREAS,
Guarantors will benefit directly and indirectly from the purchase of the Series B Notes by Holders.

NOW,
THEREFORE, in consideration of the foregoing and for other good and valuable consideration, the receipt of which is hereby acknowledged, the Guarantors covenant and agree for the
equal and ratable benefit of the Purchasers of the Series B Notes as follows:

1.Agreement to Guarantee.Each Guarantor hereby agrees, jointly and severally, to guarantee to each holder of a
Series B Note (each, a "Holder" and collectively, "Holders"), irrespective of the validity and
enforceability of the Purchase Agreement, the Series B Notes or the Obligations of Borrower thereunder, that:



1

---



2.Execution and Delivery.Each Guarantor agrees that the Guarantees shall remain in full force and effect
notwithstanding any failure to endorse on each Series B Note a notation of such Guarantee.

3.Guarantor Consolidation.Nothing contained in herein, in the Purchase Agreement or in any of the
Series B Notes (a) shall prevent any consolidation or merger of a Guarantor with or into Borrower or another Guarantor or with or into a Subsidiary of Borrower or any Guarantor hereafter
created or acquired, provided that (i) immediately after giving effect to the transaction, no Event of Default exists under the Purchase Agreement, and (ii) such Subsidiary becomes a
Guarantor hereunder, or (b) shall prevent any sale or conveyance of the property of a Guarantor as an entirety or substantially as an entirety to Borrower or another Guarantor or to a
Subsidiary of Borrower or any Guarantor hereafter created or acquired, provided that (i) immediately after giving effect to the transaction, no Event of Default exists under the Purchase
Agreement, and (ii) such Subsidiary becomes a Guarantor hereunder.

4.No Recourse Against Others.No past, present or future director, member, officer, employee, incorporator,
stockholder or agent of any Guarantor, as such, shall have any liability for any Obligations of Borrower or any Guarantor under the Series B Notes, the Purchase Agreement or this Guarantee or
for any claim based on, in respect of, or by reason of, the Obligations or their creation. Each Holder by accepting a Series B Note waives and releases all such liability. This waiver and
release are part of the consideration for issuance of the Series B Notes. Such waiver may not be effective to waive liabilities under the federal securities laws and it is the view of the
Commission that such a waiver is against public policy.

2

---

5.Governing Law.This Guarantee shall be construed and enforced in accordance with and governed by the laws of
the State of New York (other than any conflict of laws rules which might result in the application of the laws of any other jurisdiction).

6.Cumulative Remedies.The rights, remedies, powers and privileges provided to Holder herein or in the
Series B Notes or the Purchase Agreement shall not be deemed exclusive, but shall be cumulative and shall be in addition to any other rights, remedies, powers and privileges of Holder at law or
in equity.

7.Delay or Omission Not Waiver.Neither the failure nor any delay on the part of any Holder to exercise any
right, remedy, power or privilege under the Series B Notes or the Purchase Agreement upon the occurrence of any Event of Default or otherwise shall operate as a waiver thereof or impair any
such right, remedy, power or privilege. No waiver of any Event of Default shall affect any later Event of Default or shall impair any rights of any Holder. No single, partial or full exercise of any
rights, remedies, powers and privileges by any Holder shall preclude further or other exercise thereof. No course of dealing between any Holder and Borrower or any Guarantor shall operate as or be
deemed to constitute a waiver of such Holder's rights under the Series B Notes or the Purchase Agreement or affect the duties or obligations of Borrower or such Guarantor.

8.Effect of Headings.The Section headings herein are for convenience only and shall not affect the
construction hereof.

9.Severability.The provisions of this Guarantee and the Series B Notes and the Purchase Agreement are
deemed to be severable, and the invalidity or unenforceability of any provision shall not affect or impair the remaining provisions which shall continue in full force and effect.

10.Counterparts.This Guarantee may be executed in any number of counterparts, all of which taken together
shall constitute one and the same instrument, and any of the parties hereto may execute this Guarantee by signing any such counterpart.

11.CONSENT TO JURISDICTION AND SERVICE OF PROCESS.EACH OF THE PARTIES HEREBY AND EACH HOLDER CONSENTS TO THE
EXCLUSIVE JURISDICTION OF THE COURTS OF THE EASTERN DISTRICT OF PENNSYLVANIA OR MONTGOMERY COUNTY, PENNSYLVANIA AND IRREVOCABLY AGREES THAT, SUBJECT TO THE ELECTION, ALL ACTIONS OR PROCEEDINGS
RELATING TO THIS GUARANTEE OR THE SERIES B NOTES SHALL BE LITIGATED IN SUCH COURTS. THE PARTIES ACCEPT FOR THEMSELVES AND IN CONNECTION WITH THEIR PROPERTIES, GENERALLY AND UNCONDITIONALLY, THE
EXCLUSIVE JURISDICTION OF THE AFORESAID COURTS AND WAIVE ANY DEFENSE OF FORUM NON CONVENIENS, AND IRREVOCABLY AGREE TO BE BOUND BY ANY JUDGMENT RENDERED THEREBY (SUBJECT TO ANY APPEAL AVAILABLE WITH
RESPECT TO SUCH JUDGMENT) IN CONNECTION WITH THIS GUARANTEE OR THE SERIES B NOTES. NOTHING HEREIN SHALL AFFECT THE RIGHT TO SERVE PROCESS IN ANY OTHER MANNER PERMITTED BY LAW.

12.WAIVER OF JURY TRIAL.EACH OF THE PARTIES HEREBY AND EACH HOLDER WAIVES THEIR RESPECTIVE RIGHTS TO A JURY
TRIAL OF ANY CLAIM OR CAUSE OF ACTION BASED UPON OR ARISING OUT OF THIS GUARANTEE OR THE SERIES B NOTES, OR ANY DEALINGS AMONG THEM RELATING TO THE SUBJECT MATTER OF THIS GUARANTEE. THE SCOPE OF THIS
WAIVER IS INTENDED TO BE ALL-ENCOMPASSING OF ANY AND ALL DISPUTES THAT MAY BE FILED IN ANY COURT AND THAT RELATE TO THE SUBJECT MATTER OF THIS GUARANTEE, INCLUDING WITHOUT LIMITATION,
CONTRACT CLAIMS, TORT CLAIMS, BREACH OF DUTY CLAIMS, AND ALL OTHER COMMON LAW AND STATUTORY CLAIMS. THIS WAIVER IS IRREVOCABLE, MEANING THAT IT MAY NOT BE MODIFIED EITHER ORALLY OR IN WRITING, AND
THIS WAIVER SHALL APPLY TO ANY SUBSEQUENT AMENDMENTS, RENEWALS, SUPPLEMENTS OR MODIFICATIONS TO THIS GUARANTEE OR TO THE SERIES B NOTES. IN THE EVENT OF LITIGATION, THIS GUARANTEE MAY BE FILED AS A
WRITTEN CONSENT TO A TRIAL (WITHOUT A JURY) BY THE COURT.

3

---

IN
WITNESS WHEREOF, the parties hereto have caused this Guarantee to be duly executed as of the date first above written.

| |  | GUARANTORS:      
| |  | -----------------
| |  | UBIQUITEL INC.   
| |  | By:              
| |  | VIA HOLDING INC. 
| |  | By:              
| |  | VIA WIRELESS LLC 
| |  | By:              
| |  | VIA BUILDING, LLC
| |  | By:              

4

---

|ACCEPTED AND AGREED TO AS OF THE
DATE FIRST ABOVE WRITTEN BY THE
UNDERSIGNED HOLDERS: |                                                                                        | 
|------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------- | 
|BRU HOLDING CO., LLC                                                                  |                                                                                        | 
|By:                                                                                   | Name: Bruce E. Toll
Title: Member                                                      | 
|CBT WIRELESS INVESTMENTS, L.L.C.                                                      |                                                                                        | 
|By:                                                                                   | Name: Peter Lucas
Title: General Manager                                               | 
|By:                                                                                   | JOSEPH N. WALTER                                                                       | 
|BALLYSHANNON PARTNERS, L.P.                                                           |                                                                                        | 
|By:                                                                                   | Name: Bruce E. Terker
Title: President of Ballyshannon Partners, Inc., General Partner | 
|TRELLUS PARTNERS, L.P.                                                                |                                                                                        | 
|By:                                                                                   | Name: Adam Usdan
Title: President of Trellus Management Company, LLC,
General Partner  | 
|                                                                                      |                                                                                        | 
|                                                                                      |                                                                                        | 
|                                                                                      |                                                                                        | 
|                                                                                      |                                                                                        | 
|                                                                                      |                                                                                        | 

5

---

|PORTER PARTNERS, L.P.       |                                                       | 
|--------------------------- | ----------------------------------------------------- | 
|By:                         | Name: Jeffrey H. Porter
Title: General Partner        | 
|TALKOT CROSSOVER FUND, L.P. |                                                       | 
|By:                         | Name: Thomas B. Akin
Title: Managing General Partner  | 
|EXPRESS MARINE, INC.        |                                                       | 
|By:                         | Name: Richard C. Walling, Jr.
Title: Vice President   | 
|305 INVESTMENTS, L.P.       |                                                       | 
|By:                         | Name: Richard C. Walling, Jr.
Title: Managing Partner | 
|By:                         | RICHARD C. WALLING, JR.                               | 
|RUSSELL INVESTMENTS         |                                                       | 
|By:                         | Name: John Russell
Title: CEO                         | 
|                            |                                                       | 
|                            |                                                       | 
|                            |                                                       | 
|                            |                                                       | 
|                            |                                                       | 
|                            |                                                       | 
|                            |                                                       | 

6

---

|                                      |                                                                                        |  | 
|------------------------------------- | -------------------------------------------------------------------------------------- |  | 
|                                      |                                                                                        |  | 
|BALLYSHANNON FAMILY PARTNERSHIP, L.P. |                                                                                        | 
|By:                                   | Name: Bruce E. Terker
Title: President of Ballyshannon Partners, Inc.,
General Partner |  | 

7

---

QuickLinks