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Tax codes & PAYE

Checking your tax code

By Ian Robinson

Article 2 of 10

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Checking your tax code

Mistakes can arise with your code, as many of the figures shown on your coding notice are estimates and will vary according to your individual circumstances. 

If you have more than one source of income, PAYE codes may be allocated incorrectly, causing you to pay more tax than you should.

This guide explains what to do if you've seen a mistake with your tax code.

  • Get a head start on your 2016-17 tax return with the Which? tax calculator. Tot up your tax bill, get tips on where to save and submit your return direct to HMRC with Which?. 

If your tax code is wrong

Your coding notice shows all the allowances and deductions that you are entitled to, and it is this information that is used to work out your tax code. It is crucial that you check the details and notify your tax office of any discrepancies – otherwise, you may end up paying the wrong amount of tax.

To see what a coding notice looks like, and a detailed explanation of what it means, see the annotated specimen from HMRC (below):


Tax code checklist

  1. Check your tax code. Aim to sort out any problems promptly by contacting your tax office.
  2. Ensure all allowances and reliefs you are claiming are shown on your coding notice.
  3. Contact HMRC if your circumstances change – for example, if you become self-employed, you have new sources of untaxed income, or you become widowed, married or divorced – as these could affect your tax code.
  • Last updated: April 2017
  • Updated by: Gareth Shaw

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