Overpayment and tax and NI
I was overpaid in my previous employment and I am still hashing out a payment plan with my ex-employers. I don't have a problem with paying it back but I'm not sure if I trust how they are going about it. I was the one who realised that I was being overpaid not long after handing my notice in and I brought it to their attention. Now I am beginning to wish I hadn't as it is causing me a real headache and as far as I understand it, I will be left out of pocket.
I was basically overpaid £130 for five months amounting to £650 in total. This, of course, is the net amount. The amount I have to pay back is over £1,000 so I am assuming this is the gross amount. I have asked if this is the case but I have not been given an answer. If this is the case, I accept that I have to pay the gross amount back and claim the tax and NI back from the Inland Revenue but I am unsure how to go about this.
The issue I have is that my ex-employers are regarding the over payment as a loan which I am to pay back at £100 a month. As this "loan" will be an arrangement between my ex-employer and myself, I can't see that the Inland Revenue will be aware that I am owed anything back. I have spoken to HMRC and they referred me to ACAS, ACAS have referred me back to HMRC so I am spinning in circles at the moment. Should my ex-employers be communicating with HMRC as regards this? Why do they want to regard it as a "loan"?
I do not understand much about tax at all so I could be missing something so I would appreciate any advice anyone can give. At this point, I have no idea how the figures have been worked out and whether it is actually the gross. I have asked but I'm not really getting any straightforward answers, Instead, I am getting very minimal information that doesn't make any sense to me at all.