Hmm. The article doesn't actually say that they'll get an overdraft fee, just that it will be treated as overdrawn. Like, negative balance.

I'm not sure that there will actually be a fee.

While if someone took out exactly as much as they could, I suspect that it's probably pretty fair to say that it was intentional, my guess is that some people probably just went over inadvertently. I doubt that they'd want to hit the inadvertent crowd.

They might charge interest if they give notice and people don't pay it back or something, though. I could believe that.

goes looking

Yeah:

https://www.thejournal.ie/bank-of-ireland-glitch-6143834-Aug2023/

BANK OF IRELAND has said there will be “no customer detriment in relation to interest” for those who withdrew money from their accounts following a glitch with BOI’s online services.

When asked if customers who withdrew money they didn’t have from their accounts would be subject to interest rates or unauthorised overdraft fees, a BOI spokesperson said: “There will be no customer detriment in relation to interest in that scenario.”