A provision at the end of a document that recites any applicable execution formalities required for the document to take effect, and which confirms the relevant requirements have been observed. For example, in the case of a deed where the maker's signature requires attestation, the attestation clause typically states that the deed has been executed in the presence of at least one witness who attests the signatory's execution.

Also sometimes used loosely to refer to the execution clause or signature block in a contract or deed, being the place where the parties sign to confirm their agreement to its contents.