Form DS-71 at a glance
What it is: The Affidavit of Identifying Witness, identification of a passport applicant, of the U.S. Department of State.
Who signs: You, the witness, must complete items 1 through 10 (and, if applicable, 11 through 12) of this form, and sign when requested to do so by the same authorized Passport Agent, Passport Acceptance Agent, or Consular Officer who accepted the passport application.
What to bring and attach to Form DS-71
Present some form of current government-issued photo identification of your own and include a photocopy of the front and back of your government-issued photo identification.
A filled-in Form DS-71 example: a witness identifies a passport applicant

How to fill out Form DS-71, box by box
Tap a group of boxes to open it, and a picture to see it full size.
The passport applicant
Witness

Write the Witness' Name (Last, First, Middle).
Write the Witness' Residential Street Address and the City, State, ZIP Code.
Write the Witness' Place of Birth (City, State) and the Witness' Date of Birth (mm-dd-yyyy).
Write the Witness' Telephone Number and the Witness' Social Security Number.
Check No or Yes for Have you (the Witness) ever been issued a U.S. passport? If yes, continue with questions 11 - 12.
If yes, the witness' passport
Signing

Do not sign unless requested by an authorized Passport Agent, Passport Acceptance Agent, or Consular Officer.
I declare under penalty of perjury that I know or have reason to believe the above-named passport applicant is a citizen or non-citizen national of the United States; and the above statements are true and correct.
Sign on the Signature line and write the Date (mm-dd-yyyy).
More rules for Form DS-71
This form must be completed in the presence of an authorized Passport Agent, Passport Acceptance Agent, or Consular Officer.
Alteration or mutilation of a U.S. passport is punishable by fine and/or imprisonment under the provisions of 18 U.S.C. 1543, and the use of a U.S. passport in violation of the restrictions contained therein or of the passport regulations is punishable by fine and/or imprisonment under 18 U.S.C. 1544.
All statements and documents submitted are subject to verification.
Common questions about Form DS-71
What is form DS-71 for an identifying witness?
The Affidavit of Identifying Witness may be submitted with a passport application when the passport applicant is unable to establish their identity to the satisfaction of the authorized Passport Agent, Passport Acceptance Agent, or Consular Officer.
Does it need a notary?
The Acceptance Agent fills the FOR AUTHORIZED AGENT'S USE ONLY section: Subscribed and sworn to (affirmed) before me.
Is there a penalty?
False statements made knowingly and willfully on this form are punishable by fine and/or imprisonment.
Sources
[1] Form DS-71, Affidavit of Identifying Witness Identification of a Passport Applicant, U.S. Department of State (the Official source link on this page).


