An affidavit is a sworn written declaration in which a person (the affiant or deponent) attests that the contents are true, signed in the presence of a notary public, commissioner of oaths, judge, or other official empowered to administer oaths. Because the statement is made under penalty of perjury, affidavits carry evidentiary weight in courts, tribunals, and many administrative bodies without requiring the affiant to appear in person — though opposing parties typically retain the right to cross-examine.
Affidavits are common in both civil and criminal practice. Typical uses include:
- Supporting applications for search warrants, injunctions, or arrest warrants, where law enforcement sets out probable cause.
- Filing summary judgment motions, where parties submit sworn facts to show no genuine dispute exists.
- Providing documentary evidence in immigration, family law, probate, and bankruptcy matters.
- Verifying identity, residency, or financial status in administrative filings.
The form varies by jurisdiction. In common-law systems (United States, United Kingdom, Canada, India, Australia), affidavits are a standard procedural instrument; many civil-law systems instead rely on notarial deeds or déclarations sur l'honneur. In the United States, federal practice under 28 U.S.C. § 1746 also permits unsworn declarations under penalty of perjury as a substitute for notarized affidavits, simplifying filings.
For international researchers and Model UN delegates, affidavits surface in cross-border litigation, asylum claims, and international arbitration — for example, witness affidavits submitted to investor-state tribunals under ICSID or UNCITRAL rules. The Hague Apostille Convention (1961) governs how an affidavit executed in one member state is authenticated for use in another, replacing chains of consular legalization with a single apostille certificate.
Knowingly false statements in an affidavit constitute perjury, a criminal offense in nearly every jurisdiction, which is what gives the document its legal force.
Example
In 2020, election officials in several U.S. states filed affidavits in state and federal courts attesting to ballot-handling procedures during litigation over the presidential election results.
Frequently asked questions
Both contain sworn facts, but an affidavit must be signed before a notary or other authorized officer, while a declaration (e.g., under 28 U.S.C. § 1746 in U.S. federal practice) is signed under penalty of perjury without notarization.
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