What is Donor Account?
The existing current account you switch away from when claiming a bonus. Also known as a sacrificial or burner account. It's the account that gets closed during the CASS switch process. Most people keep a separate donor account that they don't use for everyday banking.
The donor account is whichever current account gets fed into a CASS switch when claiming a bonus. Because a full switch closes the account being switched, the donor is consumed by the process — its balance, direct debits and standing orders move to the new bank, and the account itself ceases to exist.
"Donor", "burner" and "sacrificial" account all describe the same thing; the terms are interchangeable in the switching community. The common thread is that it isn't the account someone runs their life from: serial switchers typically keep their main account untouched and open spare accounts to act as donors.
Where a bank allows more than one current account per customer, a second account with an existing bank can serve as a donor too. The practical requirements are set by the receiving bank's bonus terms — most often that the switch is a full CASS switch and brings the required number of active direct debits with it.