I was filling in the forms for childcare costs gathering bank statements etc to send off to HMRC and to my horror realised I had made a big error. We had been getting childcare vouchers for our son with a local childminder and I changed to paying her from childcare tax credits in September 2014. What I have only just realised is that in an award letter from August HMRC gave me money for childcare from June, so there was a period of about 10 weeks where I had been paying the childminder from childcare vouchers but also getting the childcare element for the same period (about £500 total). I can't remember the conversation with the HMRC at all, though I must have said it and I guess intended to change earlier. That whole period is very confusing as I had a high risk pregnancy and ill with twins that were born over two months early in August. The were in special care for 6 weeks and had a lot of needs when they came home. So I can't even think how I made the mistake, but it wasn't deliberate. Since September all my payment records have been fine and I have just sent it all off with an explanation. I am really worried, not about the amount, ( I just want to pay it back now). but I don't know what will happen next, how far this can go. Has anyone any advice or experience they can offer, I would be very grateful. Thanks.