We list the AER (annual equivalent rate) as it's the best way to compare rates.
Savings accounts pay interest in different ways. Most pay interest into the fixed account itself, meaning you get interest on that interest as time goes on.
But a few banks pay interest into separate accounts, meaning you don't earn interest on the interest, and so the actual rate of interest you get is slightly lower than the AER.
You might then be thinking that getting your interest paid into your fixed account is a no brainer, but it could mean you end up paying more in tax.