This has happened to me before, this time it's quite a large payment (£3+k).
I am going to ring work tomorrow to let them know that a mistake has been made. I wish they would let me keep the money as I have been so honest! They will offer to correct the money in monthly installments or take it from me in one go.
I'm feeling a bit nauseous, as if I'd been caught with my hand in the till.
What would you do if the same had happened to you?