Writing an affidavit for a friend means putting what you personally witnessed into a numbered, sworn written statement, signing it in front of a notary who administers an oath, and handing the original to your friend or their attorney to file. The document needs to stand on its own because the court cannot ask you follow-up questions, so specificity and firsthand knowledge are what give it weight.
What to Put in the Affidavit
Identify Yourself and Your Relationship
Open with your full legal name, current address, and age. Courts expect confirmation that you are a legal adult and mentally competent to give sworn testimony. Then explain how you know the person: how you met, how long you have known each other, and how often you interact. A judge reads observations from a neighbor of twelve years differently than observations from a casual acquaintance, so give the reader enough context to weigh what follows.
Stick to Firsthand Facts
Every factual statement should come from your own direct experience. Write about events you personally saw or conversations you were part of. “I was present at Thanksgiving dinner on November 28, 2024, and watched Jane help both children with their plates and sit with them throughout the meal” is a firsthand account. “Jane’s mother told me Jane is always attentive at family events” is hearsay, and most courts will disregard it or strike it from the record.
Describe facts rather than conclusions. Instead of writing that someone is “responsible with money,” write what you observed: “I helped John move into his apartment in June 2023 and saw that his rent was paid on time for the fourteen months I lived in the same building.” Let the reader draw the conclusion. Concrete observations persuade; adjectives do not. A judge in a custody case does not need to hear that your friend is a great parent; the judge needs to hear that you saw your friend help their child with homework three evenings a week.
What to Leave Out
Do not include anything you did not personally witness, even if you believe it is true. Do not speculate about the other party in a dispute or make accusations. Affidavits are evidence, and inflammatory or irrelevant statements can hurt your friend’s case more than help it. If your friend’s attorney gave you specific questions or topics, stay with those and resist the urge to editorialize.
How to Format It
Caption and Title
If the affidavit is being filed with a court, put a case caption at the top of the first page: the court’s name, the names of the parties (plaintiff and defendant, or petitioner and respondent), and the case number. Your friend or their attorney should give you this information exactly as it appears on existing filings. Copy the case number carefully; a wrong digit causes real problems.
Below the caption, center a title in capital letters: “AFFIDAVIT OF [YOUR FULL LEGAL NAME].” The first paragraph beneath the title introduces you as the affiant and states your name, address, age, that you are competent to testify, and that the facts in the document are based on your personal knowledge.
Numbered Paragraphs
Present the facts in numbered paragraphs, with each paragraph covering one distinct point. Numbered paragraphs are standard because they let attorneys and judges reference specific statements easily during proceedings. If paragraph 7 is the key fact in dispute, everyone can find it quickly. Keep each paragraph short and focused on a single observation or event.
Closing Oath and Signature Block
After the final numbered paragraph, include a closing oath. The standard language is: “I declare under penalty of perjury that the foregoing is true and correct.”1eCFR. 32 CFR 516.26 – Unsworn Declarations Under Penalty of Perjury Below that, leave space for your signature, your printed name, and the date. Reserve a separate block for the notary’s signature, seal, and commission details.
Standard 8.5-by-11-inch paper, one-inch side and bottom margins, a two-inch top margin, and a readable 12-point font such as Times New Roman are the norm. Some courts have local rules on font, margins, or page limits, so if your friend has an attorney, ask whether the court has particular requirements.
Attaching Supporting Documents
If you have documents or photographs that support your statements, attach them as exhibits. Reference each one by label in the body of the affidavit itself. For example: “Attached as Exhibit A is a photograph I took of John’s apartment on March 15, 2025.” Label the first page of each attachment clearly (Exhibit A, Exhibit B, and so on) in a corner. Every exhibit you reference should be attached, and every attachment should be referenced in the text. Loose exhibits with no connection to a numbered paragraph are likely to be ignored.
Getting It Notarized
Why Notarization Matters
An affidavit is not just a signed letter. Notarization is what turns it into sworn testimony. The notary verifies your identity, administers an oath, and certifies that you signed voluntarily. The specific notarial act used for affidavits is called a jurat, meaning the notary watched you sign and administered the oath or affirmation.2U.S. Department of State. 7 FAM 850 – Taking an Affidavit
Do Not Sign in Advance
This is the most common mistake people make. Do not sign the affidavit before you get to the notary. The whole point of the jurat is that the notary witnesses your signature in real time. A pre-signed document will be refused, and you will need to print a fresh copy.3American Society of Notaries. Physical Presence – The Foundation of All Notarial Acts
What to Bring
Bring the complete but unsigned affidavit and a valid, government-issued photo ID. A driver’s license or U.S. passport works. If you are not a U.S. citizen, a foreign passport with a machine-readable zone or a permanent resident card is generally accepted. The notary has discretion to decline an ID that appears altered or does not meet their state’s requirements.4American Society of Notaries. Presence Requirement
What Happens at the Appointment
The notary checks your ID and confirms you are the person named in the document. They administer an oath or affirmation, asking you to swear that the statements in the affidavit are true to the best of your knowledge. You then sign while the notary watches. The notary completes their section by signing, dating, and applying their official seal or stamp.4American Society of Notaries. Presence Requirement
Where to Find a Notary
Most banks and credit unions offer notary services to account holders, often at no charge. Shipping stores, postal service outlets, and local government offices such as a county clerk are other common options. Remote online notarization is now available in most states; you connect with a notary by video, present your ID on camera, and sign electronically, usually for a higher fee. Mobile notaries who travel to your location also exist and charge a travel fee on top of the notarization cost.
When You Can Skip the Notary
For federal court proceedings, you may not need a notary. Under federal law, an unsworn written declaration signed under penalty of perjury carries the same legal force as a notarized affidavit.5Office of the Law Revision Counsel. 28 USC 1746 – Unsworn Declarations Under Penalty of Perjury You format the document the same way, but instead of notarizing it you end with the specific language the statute requires: “I declare under penalty of perjury that the foregoing is true and correct. Executed on [date].” followed by your signature.
This option does not apply to depositions or oaths required before a specific official other than a notary.5Office of the Law Revision Counsel. 28 USC 1746 – Unsworn Declarations Under Penalty of Perjury Many states have adopted similar provisions for state court proceedings, but the rules vary. If your friend’s case is in state court, check with their attorney before skipping notarization. When in doubt, get it notarized.
Fixing Mistakes After Notarization
If you spot a typo or factual error in the body of the affidavit after it has been notarized, the notary cannot fix it. Prepare a corrected version and have it notarized again from scratch. For a minor clerical error in the notarial certificate itself, such as an incorrect date, the notary may be able to draw a single line through the error, write the correction nearby, and initial it, but only if their state’s laws permit. White-out or scribbling is never acceptable, and some states prohibit any alteration after the fact. For a substantive error, a new affidavit is the only clean solution.
What You Are Risking by Signing
Signing an affidavit is a legal commitment that everything in it is true. Knowingly including false information is perjury. Under federal law, perjury is punishable by up to five years in prison, a fine, or both.6Office of the Law Revision Counsel. 18 USC 1621 – Perjury Generally State penalties vary but are similarly serious, and perjury is typically charged as a felony.
Honest mistakes are not perjury. The legal standard requires that the false statement be made willfully and that it concern something material to the proceeding. If you genuinely believed something was true when you wrote it, you are not at risk. Deliberately exaggerating, fabricating events, or omitting facts you were specifically asked about can cross the line. Write only what you know to be true.
After You Sign
Once notarized, the affidavit is a complete legal document. Give the original to your friend or their attorney, who will file it with the court or submit it to the relevant agency. Before handing it over, make a photocopy that includes both your signature and the notary’s seal, and keep that copy somewhere you can find it. If questions come up months later about exactly what you swore to, you will want your own record rather than relying on memory.