I recently handed in my notice (4 weeks and worked this) and was given a CHEQUE as final finish pay which included my holiday pay on (cheque dated 03/4/07)
However, I used to be paid by BACS on 10th of each month
Imagine my suprise when I recently checked my bank account to find that I had been paid by BACS direct into my bank account on 12/004/07.
I have also received a P45!
Do I have to pay this overpayment back to my ex-employer? I think they just forgot to cancel the BACS for me!
Very probably. As with bank mistakes like this, you can't argue that you were not aware, and and they will find out about it eventually. I talk from bitter experience as today, we were all informed at work that due to an error, we have all been overpaid by �520.00 over THREE years. The joke is, they expect us to pay it back withing ten weeks at the most.
Using it, and denying knowledge, could be considered theft.
Are you sure you didn't work a month in hand, and are therefore owed this? Otherwise it depends on how big your employer is, I work for the NHS and was overpaid by �800 one month, I didn't spend it and rang the finance dept to tell them, they thanked me and said that in the whole wage bill, it wouldn't have been detected as it would be equivalent to about a 1p difference.
If you could show that you spent the money on everyday items (ie not a luxury holiday) and you didn't know you had been overpaid then you could claim equitable estoppel. If you may need a reference in the future you need to think carefully.