An eschatocol, or closing protocol, is the final section of a legal or public document, which may include a formulaic sentence of appreciation; the attestation of those responsible for the document, which may be the author, writer, countersigner, principal parties involved, and witnesses to the enactment or the subscription; or both. It also expresses the context of the documentation of the action described therein, i. e., enunciation of the means of validation and indication of who is responsible to document the act; and the final formulae.

Common in European medieval charters, they have been relegated to notarial acts, governmental acts, diplomatic treaties, certificates, and other formal documents.

Eschatocols usually contain a:

In notarial writings, the eschatocol is specifically a long form of notarial authentication, i.e., the notarization proper, and takes the form of the final clause of acts in public form or of the certificate at the end of acts in private form, typically to certify the document for use in foreign states. The words of an eschatocol are very formulaic and vary depending on the nature of the notarial act. At least in English, much of what was previously several sentences is often condensed into one.

For acts in public form, typical eschatocols read as follows:

For those in private form, the following are typical: