About this site

What this is

Tax Code Meter reads UK PAYE tax codes. You give it the string from your payslip and it tells you what that string instructs your employer to do — how much you can be paid before tax, which set of rates applies, whether it is being worked out on your year so far or on that payslip alone.

It is independent. It is not affiliated with, or endorsed by, HM Revenue & Customs or any government department, and it has no relationship with any refund-claim company.

Why it exists

Tax codes are documented, but the documentation is split across two very different kinds of source and almost nothing explains which is which. The regulations that create the codes describe them only by what they do. The letters everyone actually sees are HMRC’s naming for those functions, published separately. Reading one without the other gives you a confident answer with no way to check it.

The devolved codes make this worse. Scotland uses a scale with more bands than the rest of the UK, so its override codes do not line up with the ones most explainers describe, and two of them have no rest-of-UK equivalent at all. Wales uses rates built by a formula in the Income Tax Act rather than copied from the UK ones, which matters the moment the two diverge. A single table that flattens all three is wrong for a substantial number of readers and gives them no sign that it is.

How it is built

Every figure and every statement of law lives in one data file with its source recorded against it, and nothing is typed into a sentence anywhere on the site. That is deliberate twice over: the annual refresh becomes a change to the data rather than a search through prose, and a sentence cannot quietly keep last year’s figure after the table above it has been updated. On a site whose whole subject is short numeric strings, a stray number in a paragraph is both a stale-figure risk and invisible to every check that reads the data.

The decoder does not match codes against hard-coded meanings. It looks each code up in that same data file, and a code the file does not carry is reported as unrecognised rather than approximated to something similar. That is why an unusual code returns an honest refusal here instead of a plausible wrong answer.

What it will not do

It will not tell you what your code ought to be. That depends on what HMRC knows about your income, your benefits and your allowances, and only HMRC holds it. It does not ask for your name, your National Insurance number or your employer; what you type into it is stored nowhere and sent nowhere — the checker runs entirely in your browser.

It also takes no fee and offers no refund service. If your code is wrong, the route to fixing it is HMRC’s own, it costs nothing, and you do not need anyone to do it for you.

Corrections

Where a source is silent or contradicts itself, the relevant page says so rather than choosing quietly. If you find something here that disagrees with the legislation or with HMRC’s published guidance, the cited document governs and this site does not.