HMRC issues guidance that covers what you need to do if you stopped work. The guidance covers the main reasons that you might have stopped work, for example, being made redundant or leaving your job.
If you have been made redundant then you may have overpaid tax as a result of your redundancy payment. HMRC may in some cases refund you any overpaid tax before the end of the appropriate tax year. A claim can be made using form P50 if you are not claiming benefits and not going to work for at least 4 weeks.
However, you can’t get a tax refund straight away if you are receiving any of the following:
You should provide your local Jobcentre Plus parts 2 and 3 of your P45 and if you have overpaid tax this will usually be refunded when you get a new job (either directly by HMRC or by your new employer) or at the end of the tax year.
There is a separate process if you are leaving the UK to live abroad permanently or to work abroad for at least 12 months. A claim for an Income Tax refund is made using the P50 – Claim for repayment of tax when you have stopped working form. The link to the form has been updated.