Revenue overpaid me I suspect

Hello, I received a cheque from revenue today and I have a fair idea they have made a mistake in my favour, A few hundred euro in fact, Should I contact them and have them revise it or will they figure it out eventually, I know I should contact them but for once I just would like to come out the better, I am tax compliant in every way possible and I know I should sort this out but the greedy side of me is saying take it and run.

So, are you really asking anything here? Would you take action if you were in the reverse situation?

I'd pay it back.

When you say "they made a mistake" ... it's unlikely their computer got a calculation wrong, so I presume you mean they used the wrong data to do the calculation. Did you provide them with the right data? If so, I'd say it's not your job to be checking Revenue's calculations, so act like you didn't notice. If you misled them in any way, though, that is a dangerous road to be going down.

Salaried
Isn't an unexpected cheque from revenue sweeter than any other cheque you ever received. I would also be very tempted to do nothing and then pinch myself and think of their powers and then very reluctantly query it and finally return it

If Revenue have issued you a refund and this is not a result of any incorrect claim by you, there should be no reason for you to send it back. The worst that can happen in this instance is that they may subsequently realise their mistake and re-take the funds through your tax allowance. From your post there is no indication that this is clearly an error by Revenue!

If they sent you a cheque for 10k then that might be a problem, but not a few hundred. I'd just assume that they are competent and that I was indeed due a refund. If they came looking for it down the line, and they wouldn't, I'd just pay it back. A bet to nothing methinks.

Gentlemen,
Revenue are quite capable of issuing refunds in error. However if you are concerned, you can contact them and they can check the ITS system and with the CG's in limerick. If it is a mistake, it can be resolved quickly. Its not the first time and will not be the last. I speak from a great deal of experience in this area.