Tax on final pay

Good evening All, I've searched all over for advice but can't find what I'm looking for. I've recently been dismissed from my employer and they are about to give me my final pay, holiday pay, outstanding overtime and expenses all in one month. This will be about 4 times my usual salary. I'm worried that I will be taxed on all of this if the tax office thinks I earn that month each month for the year. I understand I have to pay tax but this is not a usual amount I would earn. Thank you for any guidance

Hi Dav
If you receive a larger final payment the taxable element will be taxed at that time. If you start a new job and return to your standard salary any tax overpaid will be refunded over the remainder of the tax year. 
Thank you.