Terms
This site is information, not advice, and the documents it cites govern rather than the page you are reading.
Information, not advice
This site explains how UK PAYE tax codes work. It does not give tax advice, financial advice or legal advice, and using it does not create a professional relationship of any kind. If your circumstances are complicated or a lot of money turns on the answer, speak to an accountant or a tax adviser.
The cited documents govern
Every substantive statement here is tied to a provision of the Income Tax (Pay As You Earn) Regulations 2003, the Income Tax Act 2007, or a named HMRC publication. Where this site and one of those documents disagree, the document is right and this site is wrong. The sources page lists all of them so you can check.
The figures are unsigned
The figures and rules here are taken from those sources and shown as they were found. They have not been signed off by a reviewer. They are believed to be an accurate reading, and no warranty is given that they are complete, current or correct for your situation.
Your own code
Nothing here tells you what your tax code is or ought to be. Only HMRC holds that, in your Personal Tax Account. Do not act on a conclusion drawn from this site without checking it against your own coding notice.
Not HMRC
This site is independent. It is not affiliated with, endorsed by, or operated on behalf of HM Revenue & Customs or any government department, and it is not connected to any tax-refund company.
Availability
The site is provided as it is, without any guarantee that it will be available, uninterrupted or error-free.
Independent tool not affiliated with HMRC. For your official code, log in to your Personal Tax Account. Check your tax code on GOV.UK.
The figures and rules on this site are taken from the Income Tax (Pay As You Earn) Regulations 2003, the Income Tax Act 2007 and HMRC’s published guidance, and are shown as they were found. They have not been signed off by a reviewer. Where the law and HMRC’s naming differ, the page says which is which rather than blending them. For anything that affects a decision, the cited document governs and this site does not.