It’s always worth ensuring that you fully understand how a savings account works before you apply for it, but it’s especially important to check how interest is being advertised. A bank should always advertise the gross rate of interest as well as the AER, and while these percentages can be the same, they could be different. If you compare savings accounts from two different banks, but you compare the gross interest rate from one account with the AER from another, you may end up with a misleading comparison.