The Difference Between an Affidavit and a Declaration

The difference between an affidavit and a declaration comes down to how you execute it: an affidavit is a written statement you swear is true in front of a notary or other authorized official, while a declaration is a written statement you sign on your own, directly above a line stating it’s made under penalty of perjury. Both carry the same exposure to perjury charges if you lie, and courts that accept either treat them as equivalent evidence. The practical question is which one the court, agency, or institution receiving your document will accept.

How Each Document Is Executed

An affidavit requires a short ceremony. You appear before someone legally authorized to administer oaths (usually a notary public, sometimes a judge, court clerk, or certain government officials), verbally swear or affirm that everything in the document is true, and sign it while that official watches. The official checks your identification, witnesses the signature, and adds their own signature with an official stamp or seal. The oath cannot be taken on anyone else’s behalf, and the affiant must be physically present with the notarizing officer.1U.S. Department of State. 7 FAM 850 Taking an Affidavit The person making the statement is called the affiant.2National Institute of Justice. Law 101: Legal Guide for the Forensic Expert – Legal Requirements of an Affidavit Remote online notarization has made the in-person part easier in most states, though not every receiving party accepts remotely notarized documents.

A declaration skips the ceremony. It gets its legal weight from one specific sentence placed just above your signature. Federal law prescribes the exact wording. Inside the United States, the line reads: “I declare (or certify, verify, or state) under penalty of perjury that the foregoing is true and correct. Executed on (date).” If you’re signing outside the country, you insert “under the laws of the United States of America” after “penalty of perjury.”3Office of the Law Revision Counsel. 28 USC 1746 – Unsworn Declarations Under Penalty of Perjury Getting the wording wrong, or leaving out the date, gives the other side grounds to challenge your filing.

What That Difference Means in Practice

Everything else flows from the execution question.

  • Cost. Most states cap standard notary fees between $2 and $15 per signature, and mobile or after-hours notaries charge more. A declaration costs nothing beyond printing and signing.
  • Timing. You can sign a declaration at midnight on a Sunday. An affidavit requires coordinating with a notary’s availability, even with remote options.
  • Third-party involvement. An affidavit always involves a notarizing official who verifies your identity and witnesses the signature. A declaration is self-authenticating.

Neither document is legally “stronger” than the other. Both create the same perjury exposure, and properly executed versions carry equivalent evidentiary weight in the proceedings where they’re accepted.

When a Declaration Is Enough

Under 28 U.S.C. § 1746, wherever a federal law, rule, or regulation calls for a sworn written statement, an unsworn declaration under penalty of perjury has “like force and effect.”3Office of the Law Revision Counsel. 28 USC 1746 – Unsworn Declarations Under Penalty of Perjury That’s why declarations are the standard in federal litigation. If you’re filing a motion in federal court and need to attach a sworn statement, a declaration almost always works.

The statute carves out three situations where a declaration cannot substitute for an affidavit: depositions, oaths of office, and any oath that must be taken before a specific official other than a notary public.3Office of the Law Revision Counsel. 28 USC 1746 – Unsworn Declarations Under Penalty of Perjury A deposition requires sworn testimony before an officer; you can’t submit a written declaration and call it one.

When an Affidavit Is Still Required

State courts are a patchwork. A growing number of states have statutes similar to 28 U.S.C. § 1746, but the scope varies widely. Some allow declarations broadly, some restrict them to certain professions or case types, and a few have no general declaration statute at all, meaning affidavits remain the default.

Even in states that accept declarations, certain contexts still call for an affidavit:

  • Family law financial disclosures. Many state family courts require sworn financial affidavits in divorce and custody proceedings.
  • Probate matters. Verifying a will or establishing facts about a decedent’s estate often requires a notarized affidavit.
  • Real estate transactions. Title companies and county recorders frequently require affidavits to confirm ownership, boundaries, or the absence of liens.
  • Immigration. When primary identity documents are unavailable, USCIS requires at least two sworn affidavits from people with direct personal knowledge of the facts.4USCIS. Chapter 4 – Documentation

Affidavits also show up outside court entirely, in vehicle title transfers, license applications, insurance claims, and business transactions where the receiving party wants the extra verification a notary provides. Check the specific requirements of whatever court, agency, or institution will receive your document before deciding. Submitting a declaration where an affidavit was required can get your filing rejected or stricken, forcing a redo and possibly a missed deadline.

The Perjury Risk Is the Same

Lying in either document carries the same basic consequence. Under federal law, anyone who knowingly makes a false material statement under oath or in a declaration under penalty of perjury in a court proceeding faces up to five years in prison.5Office of the Law Revision Counsel. 18 USC 1623 – False Declarations Before Grand Jury or Court State perjury statutes impose their own penalties, generally as felonies.

The absence of a notary doesn’t make a declaration lower-stakes. Congress designed 28 U.S.C. § 1746 so declarations carry the same legal force as sworn statements, and 18 U.S.C. § 1623 explicitly covers false declarations. Courts don’t treat one document more skeptically than the other when both are properly executed.

Avoiding Execution Mistakes

Most challenges to affidavits and declarations aren’t about the substance. They’re about execution errors that hand the other side an easy objection.

  • For affidavits, sign in the notary’s presence, not beforehand. The notary needs to watch you sign. A competent notary will refuse to notarize a pre-signed document, and if they don’t, the affidavit is vulnerable to challenge.1U.S. Department of State. 7 FAM 850 Taking an Affidavit
  • For declarations, use the exact perjury language from 28 U.S.C. § 1746, include the date of execution, and use the correct version (domestic or international). Paraphrasing the perjury statement or omitting the date gives opposing counsel an opening to move to strike.
  • For both, stick to facts you personally know. Secondhand statements are the most common reason these documents get challenged or excluded. If you need to include something you learned from someone else, say so explicitly and identify the source.