Abstract: In a trade settlement system that uses one or more computers, for a bilateral contract including both obligations of a change of name of a vesting destination from one party to another party of contract parties, the change of name accompanying a transfer of ownership of an article to be sold or purchased in a trade, and settlement using predetermined electronic money for a consideration relating to the sale and purchase, each of the one or more computers includes: a settlement processing unit that performs the settlement by using a smart contract on a blockchain; and a processing unit that processes the change of name by using the smart contract on the blockchain, in a case where the settlement has been successful.