I've had a letter from HMRC saying I need to pay back Tax Credit payments they made to me for YE 2004. The amount is nearly 6k. No reason has been specified, it's one of those computer-generated form letters (actually what I've had is a letter saying they've demanded payment and I haven't done anything about it, when I've not had any such demand - but that's a different story).
If it emerges that I must pay it back, the period (from their website) they seem to allow the repayment over is 12 months - that's around 500/ month! Is there any chance that I will be allowed to pay back smaller monthly amounts? What grounds exist for disputing such a demand? I'm really not sure why I'm being asked to pay them back. (In their telephone queue as I type this.) For example, is there any limitation on how far back the Revenue can go to re-claim purported overpayments?
It's a substantial sum of money, so any helpful advice would be most welcome.
TIA Zippy