I work in the public sector. From 2007-2008 I was significantly overpaid.
I notified my employer immediately, but the overpayments continued. Finally they stopped and I had to wait for them to issue an invoice to pay the money back. This took years.
Anyway, I lost track of how much I'd been overpaid and simply paid the invoice.
It's only just occurred to me that I would have paid tax on the overpayments and I should have claimed it back at the time.
From what I can find online, there's a 4 year limit on tax rebates. Is there any way round this?