I am not sure you have all your facts correct. Barclays haven't ever done an overdraft at 5%. The lowest I have seen them do is a Barclays Bank base rate linked overdraft for Premier clients and this rate is BBBR plus a margin.... certainly higher than the 5% you are quoting. If you have a fee-paying account then you may get some interest free portion, then on the remainder it will be 9.9% apr. If you have a standard account, it will be 17.9% apr.