Thanks for this. The bad news is that 'no' the bank hasn't broken the law or any regulatory guidelines - not yet anyhow. The OFT is investigating the subject of charges for late payments; overdrafts etc but as of yet it is not clear what their recommendations will be. As far as fees go, exceeding your authorised overdraft limit is the 'Big Daddy' of them all. Apart from being subjected to an immediate fee and whacking rate of interest - pretty much the norm, further fees immediately follow for each transaction occurring whilst still in the unauthorised overdraft. Accordingly the fees build quickly although many providers have a 'cap'. Even so, your penalty of £75 is 'run of the mill' stuff albeit it will hardly be welcome. It's definitely worth arguing your case and objecting to the fee - the bank may waive it or reduce it. Unauthorised overdraft charges are nothing other than 'grim' and they can hit those struggling with their finances hardest. The banks know that if someone is frequently overdrawn they may find it difficult to switch their current account to another provider. This means, for some, they'll know that if you threaten to switch your account to another bank it's an empty threat.