Hi Welcome to the forum,
I believe this would be classed as a windfall and would need to be paid in, some windfall clauses have a £500 clause that anything over that needs to be paid, mine doesn't I have to pay everything over, check your chairman's report / proposal which should give details.
If life is what you make it, I must have been in a strange mood when I made mine
I claimed back a load of money. Never actually saw any of it though as they just knocked it off my balance. Still it meant less was needed for my F&F, and I felt a lot happier at getting my own back at the bank!