In the statutory law of wills and trusts, an attestation clause is a clause that is typically appended to a will, often just below the place of the testator's signature. It is often of the form signed, sealed, published, and declared, a legal quadruplet.

United States

In the United States, attestation clauses were formally introduced into probate law with the promulgation of the first version of the Model Probate Code in the 1940s. Statutes that authorize self-proved wills typically provide that a will that contains this language will be admitted to probate without affidavits from the attesting witnesses. An attestation clause modeled on the Model Probate Code's language might provide: The validity and form of an attestation clause is usually a matter of U.S. state law, and will vary from state to state. Many states allow attestation clauses to be added as codicils to wills that were originally drafted without them.

Other uses

Often synonymical with witness, an attestation "testifies to the accuracy or authenticity of something". Thomson Reuters define an attestation clause as where "a document has been executed in the presence of one or more witnesses (who attest the execution)".