cost of notarising and legalising a document
To have a document authenticated: 1  The document must be either notarized by a DC notary public or signed by an authorized head of a DC government agency. 2  The Office of Notary Commissions and Authentications does not notarize documents.3  The cost is $15 per document, payable by check, money order or Visa or Master Card. The document must be either notarized by a DC notary public or signed by an authorized head of a DC government agency. 2  The Office of Notary Commissions and Authentications does not notarize documents.