Hi. I started work last year, but for some reason I don't seem to have been added straight away to the payroll. I was given an advance while it was sorted out, then paid three months salary in one go, with the advance deducted.
This has meant I paid far too much tax and N.I because I had a monthly tax code so only got one month's worth of allowance even though it was for three month's wages.
The tax will sort itself out when my P60 is issued. However, I'm not sure what will happen with the N.I. can you claim a refund or does it happen automatically like for tax? As this is a couple of hundred pounds I'm quite worried.