Charterparty. This is the document that contains the details of the charter or contract. While the shipowner and charterer are called the "parties to the charter", the word "party" in "charterparty" originates from the old Latin phrase for the contract to use a ship.

The phrase was "carta (or "charts") partita" which signified that it was a divided document in more than one "part" because facilities for making copies were not easily available in those times.

Standard-form charterparties are common today for various types of contracts and different trades. These have printed clauses and can have "rider clauses" added after negotiation between the parties to the contract. Shipowners' liability insurers, P. & I. (or Mutual) Associations, generally advise that standard forms of charterparties should be used because the clauses are the result of many years' experience and decisions of various courts when disputes have arisen. Various bodies publish standard-form charterparties, such as BIMCO. BIMCO also has a system where the organisation approves or supports charterparties published by other organisations.