In October he received a letter from the bank stating that his overdraft had been reduced from £1000 to £500. Annoying, but it's happening to a lot of people. The last bank statement that arrived (December) had the new overdraft limit printed on it and showed that he was about £40 into said overdraft.
He pays all his bills by direct debit, so he was a bit mystified today when one company asked him where the heck their payment was (not in those words!). When he went to the bank to find out what was happening, he discovered that they had decided to cancel his overdraft altogether. Just like that. No letter like last time. When he asked if he could give them the £40 and close the account, they refused because that £40 was an 'unauthorised overdraft' and he has to pay penalty charges. The bank lady said she couldn't do anything, even though he explained that it was authorised at the time the money came out.
Luckily he has another account at a different bank, so has paid the late bill, and won't starve until the next pay day. The bank might not have done anything wrong technically, but he's going to write to the complaints department and see if the penalty charges can be waived.
(Edited because I can't spell.)
EDIT TO CLARFY: The US-UK divide causes confusion again! In the UK, people are allowed an overdraft of a certain amount that their bank agrees to, without penalty. It's basically credit. In my bf's case, his allowed overdraft as of the beginning of December was £500. He used £40 of it, meaning his account balance was -£40. Then at some point in mid to late December, the bank removed the overdraft facility entirely, didn't tell him, and want him to pay penalty fees because he didn't read their mind.