How do you retrieve an old Clash of Clans account?

To retrieve an old Clash of Clans account, you need to contact Supercell Support. They will require information such as the username, the town hall level, the clan name, and any purchase receipts associated with the account. If you have linked your account to a google Play or Game Center account, you can try logging in through those platforms as well. Be prepared to provide as much detail as possible to prove ownership of the account.