An affidavit is a written statement of facts that its maker confirms by an oath or affirmation before a person authorized to administer it, such as a notary public. If someone has asked you for an affidavit, first check whether the recipient needs that sworn document or permits a signed declaration under penalty of perjury instead.

The federal court's affidavit definition identifies the written statement, the maker's oath and the authorized officer. The document's title alone does not tell you which signing process will work: the applicable law, court rule, agency instructions and requested form matter.

Affidavit, Declaration, Oath and Affirmation

In federal statutory usage, 1 U.S.C. §1 includes affirmation within “oath” and affirmed within “sworn,” unless context indicates otherwise. California's jurat rules expressly permit either an oath or affirmation. Terminology can differ elsewhere, so do not assume every form labeled “declaration” or “affirmation” follows the same procedure.

Three Questions Before Choosing a Form

1. Who will receive it, and for what purpose? Identify the court, agency or other recipient, the case or request, and the required current form.
2. Which law or instruction controls the signing route? Find out whether a sworn affidavit is needed or an unsworn declaration is allowed. A general federal alternative does not automatically answer a state or foreign request.
3. Who can truthfully make the required statements? Choose the person with the relevant knowledge or required role. Someone else typing the document does not turn them into the witness or authorize them to sign for the maker.

These are practical preparation questions, not a universal three-part legal validity test. If instructions conflict or are unclear, ask the recipient or obtain local legal help before signing.

When Affidavits and Related Declarations Are Used

These examples show why there is no single affidavit suitable for every court, bank or agency. Do not use a general template to replace a required form, and do not assume a document called an affidavit is simply a notary appointment.

Personal Knowledge: Facts You Can Actually Explain

Personal knowledge means knowing a fact through your own observation or experience, rather than presenting an assumption or another person's account as something you witnessed. State how you know the relevant facts and distinguish estimates, records and secondhand information when the form or rule permits them.

For federal summary judgment, Rule 56(c)(4) requires an affidavit or declaration based on personal knowledge, facts that would be admissible in evidence and a showing that the maker is competent to testify about them. That is a specific evidentiary rule, not a claim that every document called an affidavit uses identical requirements.

Example. A person who watched a package arrive could describe the date, the location, what they saw and how they recognized the package. “I saw the driver place a sealed parcel beside the front door at approximately 2 p.m.” supplies an observation. “The driver must have damaged it earlier” adds an unsupported inference if the maker did not see that happen.

Use numbered, factual paragraphs where appropriate, identify the relevant records or exhibits, and avoid turning the statement into argument. Do not add facts merely because they would help someone's case. The decision about whether evidence may be used remains separate from notarization.

Jurat Versus Acknowledgment: Different Notarial Acts

A notary public must perform the required act, not simply add a seal to whichever paper you bring. California provides a useful concrete distinction:

Under California Government Code §8202, the notary administering a jurat must give the oath or affirmation, verify the maker's identity using the required evidence, and have the maker sign in their presence. Its certificate does not certify that the underlying facts are truthful, accurate or legally valid. The notary's duties and the maker's responsibility for the facts are different.

The 2026 California Notary Public Handbook explains both acts and warns that a jurat cannot be added to a paper merely mailed or delivered to the notary without the signer appearing, taking the oath and signing in their presence. Do not substitute an acknowledgment where a jurat is required. Check local electronic or remote-notarization authorization before assuming that a scan, online signature or ordinary video call completes the required act.

A notarial commission itself does not qualify someone to choose your legal document or give legal advice. California's handbook directs notaries asked to perform those legal tasks to refer the requester to an attorney. Get the recipient's required form or appropriate legal guidance rather than asking for a seal to solve a form-choice problem.

When an Unsworn Declaration Can Be Used

In many federal matters, 28 U.S.C. §1746 permits a dated, signed declaration under penalty of perjury to support a matter otherwise requiring a written sworn statement. It has express exceptions: a deposition, an oath of office, and an oath required before a specified official other than a notary public.

For execution within the United States, its territories, possessions or commonwealths, the statute provides wording substantially in this form:

I declare under penalty of perjury that the foregoing is true and correct. Executed on [date]. [Signature].

The statute uses a different version for execution outside the United States, expressly invoking United States law. Use the correct statutory route and the recipient's requirements; do not copy the domestic wording into every overseas or state filing. A normal signed letter without the required certification is not the same thing.

California has its own alternative in Code of Civil Procedure §2015.5, including specified exceptions and execution wording/date rules. California's official Declaration form MC-030 has space for facts, case information, a date, the maker's name and signature, and a certification under California law. It illustrates a state declaration route; it is not a federal affidavit form or a promise that every California filing can use that blank form.

Decision example. If a federal court permits a §1746 declaration for a motion, the person with the relevant knowledge can prepare the permitted signed and dated declaration without arranging an administered oath. If the recipient instead requires a properly sworn affidavit and that alternative does not apply, arrange the authorized officer and required jurat process. The factual account still needs to satisfy the applicable evidentiary requirements either way.

Drafting and Completion Checklist

• Get the recipient's current form and instructions; confirm the jurisdiction, case number, purpose and submission requirements.
• Identify the maker and explain their relevant knowledge or role. Separate firsthand facts from estimates or information attributed to others.
• Use accurate dates, locations and specific factual details. Label referenced exhibits consistently and check any attachment instructions.
• Choose the lawful signing route. For a required jurat, arrange the oath or affirmation and signing before the authorized officer; bring the identification required locally.
• For an allowed unsworn declaration, use the required certification, date and signature, including the correct jurisdiction or overseas wording.
• Read the entire statement before signing. Check that names, dates, amounts, exhibits and statements agree with the supporting material.
• Follow filing or delivery instructions and keep a copy of the signed document. Obtain local help for disputed facts, unfamiliar legal commitments or unclear signing requirements.

This checklist supports preparation; it does not replace a court's rules, an agency's instructions or professional advice about what should be asserted.

Mistakes That Can Make the Document Unusable

Check for the wrong form or edition, missing signatures or dates, a missing truth certification, a mismatched case number, unsupported facts and missing required attachments. For notarized affidavits, check the required certificate and signing process: a seal without an administered oath or affirmation is not a completed jurat.

A valid notarial act and an acceptable filing are separate checks. The California identity certificate does not establish the facts, and federal Rule 56(c)(4) imposes evidentiary requirements beyond signing. Acceptance and any opportunity to correct defects depend on the recipient and applicable procedure; do not assume notarization guarantees admission or that every error has the same consequence.

False Statements and Perjury

Signing makes the truth commitment serious. Under 18 U.S.C. §1621, willfully affirming a material matter the maker does not believe true can constitute federal perjury in the circumstances the statute specifies, including qualifying §1746 declarations. State laws and other federal provisions may differ. An innocent typo is not automatically the same as the willful, material falsehood described in that statute.

Do not sign information you know is false, present guesses as observations, or assume a notary takes responsibility for your account. If you discover an error, seek the appropriate correction procedure rather than altering an already signed or filed document without checking the rules.

Common Questions

Can I write my own affidavit? You can prepare a factual draft, but the maker must be the appropriate person and the completed document must satisfy the recipient's form and execution requirements. Writing it yourself does not dispense with a required oath, officer or certificate.

Does every affidavit or sworn statement need a notary? Not necessarily a notary specifically: the applicable law may authorize another officer, and a permitted unsworn declaration may be a different route. Confirm what the recipient actually requires.

How do I get an affidavit? Start with the requesting court, agency or organization. Obtain its current form, identify the right maker, prepare accurate facts, then arrange the required officer or permitted declaration process.

How much is the notary fee? Fees vary. California Government Code §8211(b) caps administering an oath or affirmation to one person and executing the jurat, including the seal, at $15. That is a California notarial-act limit, not a nationwide price for preparing, filing or obtaining an affidavit; ask what services a quoted charge covers.

What notary mistake should I watch for? There is no universal ranking here. A particularly useful check is whether the required act was actually performed: an acknowledgment, a seal and a jurat are not interchangeable.

This page gives general information and specific U.S. examples, not advice about your statement, case or obligations. Rules vary by state, country and filing forum. Check the controlling requirements before signing or submitting.