Find My Tax Code: Five Places HMRC Hides It

Your March payslip arrived and the tax deduction looks odd. You want to check your tax code, but you have no idea where HMRC actually put it. You are not alone, and the confusion is not your fault.

Finding your tax code should take thirty seconds. Instead, most employees spend twenty minutes clicking through government websites, ringing HMRC's famously understaffed helpline, or simply giving up. This article shows you exactly where your tax code lives, what to do once you find it, and how to tell whether it is correct or whether it is quietly draining your pay packet.

Tax Code

A combination of numbers and letters issued by HMRC to your employer, telling them how much income tax to deduct from your wages each pay period. The number element represents your tax-free personal allowance (divided by ten), while the letter reflects your circumstances, such as whether you have one job (L), multiple jobs (T), or are a Scottish taxpayer (S).

Where Exactly Is Your Tax Code?

HMRC does not put your tax code in one obvious place. It scatters it across multiple documents and systems, some digital, some paper, some dependent on whether your employer has filed anything yet. Here are all five locations, in order of how quickly you can access them.

1. Your Most Recent Payslip

This is the fastest route. Your payslip should show your tax code in a dedicated field, usually labelled "Tax Code" or "Tax Ref". It will look something like 1257L, BR, or 0T. If your employer uses payroll software, the code is almost certainly there.

The catch: some payslip layouts are genuinely terrible. If you receive a paper payslip from a smaller employer, the tax code is sometimes printed in a tiny font beneath the deductions table, or abbreviated without a label. Look for a four-digit number followed by a letter. That is almost certainly it.

If you are paid weekly, each payslip should show the same code unless HMRC has issued a new one mid-year. A sudden change in the number on a payslip is worth investigating immediately.

2. Your P60

Your employer is legally required to issue a P60 by 31 May each year. It summarises your total pay, total tax deducted, and your tax code for the tax year just ended. If you want to find your tax code for the previous year rather than the current one, the P60 is the definitive source.

One important nuance: your P60 shows the code that was in place at the end of the tax year (5 April). If HMRC changed your code in, say, February, your P60 will reflect that updated code, not the one you had in April of the previous year. This matters if you are trying to piece together a multi-year picture.

3. Your P45

If you left a job during the tax year, your former employer should have issued a P45 within a few days of your final pay. Section 2 of the P45 shows your tax code at the point of leaving. This is particularly useful if you started a new job and your new employer has temporarily put you on an emergency tax code (often 1257L W1/M1 or 0T) while waiting for HMRC to issue the correct one.

If you can hand your new employer a P45 promptly, they can apply the correct code from day one and save you from an emergency code that over-deducts tax each month.

4. A HMRC Tax Code Notice Letter (Form P2)

Every time HMRC changes your tax code, it sends you a document called a PAYE Coding Notice, officially known as a P2. The letter explains what code has been issued and why, listing adjustments such as underpaid tax from a previous year, taxable benefits like a company car, or a claimed expense such as professional subscriptions.

P2 notices are sent to your home address. If you have moved house without updating HMRC, these letters are going somewhere else. HMRC will not chase you to confirm receipt. The code still goes to your employer, regardless of whether you ever saw the explanation for it.

This is one of the most common reasons people end up on an incorrect code for an entire tax year without realising it.

5. Your HMRC Personal Tax Account Online

This is the most complete and current source. Log in at gov.uk/personal-tax-account using your Government Gateway credentials. Under the "PAYE Income Tax" section, you will see your current tax code for each active employment. You can also view previous codes, see why adjustments were made, and tell HMRC directly if something is wrong.

If you have never set up a Personal Tax Account, you will need a Government Gateway ID, which requires a passport or driving licence for identity verification. The setup takes roughly ten minutes and is worth doing even if only to check your code once.

Alternatively, you can check your tax code free at /check-my-tax-code without navigating HMRC's somewhat labyrinthine portal architecture.

Why Your Tax Code Might Be Wrong

Finding your tax code is step one. Understanding whether it is correct is step two, and this is where most people stop. HMRC sets codes automatically based on information it holds, but that information is often out of date.

Common reasons for an incorrect code

You changed jobs. When you start a new job without a P45, your employer often applies an emergency code until HMRC sends the correct one. Sometimes the correct notice never arrives in time, or your employer continues using the emergency code by accident.

You have more than one income source. If you have a second job or a pension alongside employment, HMRC needs to split your personal allowance between income sources. It frequently gets this wrong, giving you the full £12,570 personal allowance against both incomes, which means you underpay tax on one and overpay on the other.

You claimed a taxable benefit. Company cars, private medical insurance provided by your employer, and interest-free loans above £10,000 all reduce your personal allowance. If your employer reported a benefit to HMRC and HMRC adjusted your code without you noticing, your take-home pay dropped and you may not know why.

You have underpaid tax in a previous year. HMRC sometimes collects previous underpayments by reducing your current year personal allowance. The P2 notice explains this, but if that letter went to a previous address, you are paying more tax this year with no idea why.

Your circumstances changed. Marriage, divorce, a new child, starting or stopping a side income, these all potentially affect your tax code. HMRC does not know about these changes unless you tell it.

What the Letters in Your Code Mean

Once you find your tax code, the number part tells you how much tax-free income you get (multiply by ten). The letter tells you why. For a deeper dive into this, Tax Code Numbers: What Each Digit Actually Means is worth reading alongside this article.

The most common codes to recognise:

• 1257L is the standard code for most employed adults with one job and no unusual adjustments. It reflects the current personal allowance of £12,570.
• BR means Basic Rate: all your income from this source is taxed at 20% with no personal allowance applied. Common for second jobs.
• 0T means your entire income is taxed with no allowance at all. This is an emergency code and nearly always means you are overpaying.
• K codes are negative allowances. They appear when you owe tax on benefits or previous underpayments that exceed your personal allowance. A K code means your taxable income is actually increased, not reduced.
• W1 or M1 after a code number means your employer is taxing you on a week-by-week or month-by-month basis rather than cumulatively across the year. This emergency basis prevents an end-of-year catch-up and can leave you overpaying.

If you see anything other than 1257L and you do not understand why, that is your cue to investigate. Your Tax Code Is a Message from HMRC. Can You Read It? walks through the message decoding in detail.

What to Do Once You Have Found Your Code

Step one: cross-check with your circumstances

Ask yourself: do I have one job, no taxable benefits, no side income, no outstanding underpayment from a previous year? If yes, and you are a standard-rate English taxpayer, your code should be 1257L. If it is anything else, you need to understand why.

Step two: read the P2 notice

If HMRC adjusted your code, the P2 explains the reasoning. Look at what adjustments have been made and whether they reflect your actual situation. Common errors include benefits that have ended but are still in the code, or underpayment figures that have already been paid.

Step three: tell HMRC if something is wrong

You can challenge your tax code through your Personal Tax Account online, by calling HMRC on 0300 200 3300, or by writing to HMRC's Pay As You Earn and Self Assessment office in Benton, Newcastle. If you have a specific, documented reason why the code is wrong (a benefit that ended, a second job you no longer hold), HMRC is generally quick to issue a corrected notice.

For a detailed walkthrough of each method, How to Change Your Tax Code: Four Routes, One Goal covers the process step by step.

Step four: claim a refund if you have overpaid

If your code was wrong for a previous year and you overpaid tax, HMRC will usually refund automatically at the end of the tax year through a P800 reconciliation letter. If you have not received a P800 but believe you overpaid, you can claim directly through your Personal Tax Account or by post using form R40.

HMRC will go back four tax years. For someone who was on an emergency 0T code for twelve months on a salary of £35,000, the overpayment could be well over £1,000. That is a refund worth chasing.

If you want to see what you should have been paying, the salary tax calculator at TapTax lets you model different tax codes and see the difference in take-home pay.

A Real Scenario: When Finding Your Code Reveals a Problem

Consider a hospital receptionist earning £28,000 who also has a small rental income of £4,000 per year. HMRC knows about the rental income because she disclosed it during a brief stint on Self Assessment a few years ago. HMRC includes a tax adjustment in her PAYE code to collect the tax on that rental income through her wages. So far, logical enough.

Then she moves house. The P2 notice for the new tax year, which shows her code has been adjusted to collect an additional £800 in underpayment from two years ago, goes to her old address. She sees a lower take-home pay but assumes it is a National Insurance change. She does not check her code because she does not know where to find it.

Two tax years later, she finally checks her Personal Tax Account (prompted by a friend who got a refund after doing the same). She discovers the £800 underpayment was collected correctly, but also that the rental adjustment has been applied at the wrong rate. She has effectively been paying tax on £4,800 of rental income rather than £4,000. Over two years, that is a £160 overpayment at the basic rate.

Small money, perhaps, but it was her money. And it took fifteen minutes to recover once she knew where to look.

If you have multiple income sources, the multiple income tax calculator can help you model what your combined tax liability should be and whether your current code reflects it accurately.

People also ask

How do I find my tax code if I have lost my payslip?

Log into your HMRC Personal Tax Account at gov.uk/personal-tax-account. Under the PAYE Income Tax section, you will see your current tax code for each active employment. Alternatively, check any P60 from the previous tax year, or call HMRC on 0300 200 3300 with your National Insurance number ready.

What does it mean if my tax code says BR or 0T?

BR means all income from that source is taxed at the basic rate (20%) with no personal allowance applied. 0T means no personal allowance at all, with tax applied at all relevant rates. Both are often emergency codes applied when HMRC lacks information about your employment. Both typically mean you are overpaying tax and should contact HMRC to issue the correct code.

Can my tax code change during the year?

Yes. HMRC can issue a new tax code at any point during the tax year, usually in response to new information such as a reported benefit, a change in employment, or a correction to a previous underpayment. Your employer is required to apply the new code from the date HMRC specifies. You should receive a P2 notice explaining the change, though it is sent to your home address, so an outdated address on HMRC's records means you may not see it.

How far back can I claim a tax refund if my code was wrong?

HMRC allows claims for overpaid income tax going back four tax years. For example, in the 2024/25 tax year, you can claim back to 2020/21. Refunds for more recent years may be issued automatically via a P800 letter after the tax year ends; for older years you will usually need to submit a formal claim through your Personal Tax Account or by post.

The Bigger Picture: Why This Matters Beyond One Payslip

HMRC's PAYE system is, in principle, designed so that most employees pay the right tax automatically. In practice, it relies on a chain of accurate information: your employer reporting your benefits correctly, HMRC processing that information promptly, the P2 notice reaching you, and you understanding what it says.

Every link in that chain breaks with some regularity. HMRC itself acknowledged in its 2022/23 accounts that end-of-year PAYE reconciliations identified underpayments and overpayments running into the hundreds of millions of pounds. Most of those discrepancies started with a tax code that did not match reality.

The system is not designed to alert you when your code changes in a way that costs you money. It is designed to collect tax. Checking that the collection is accurate is, apparently, your job.

The good news is that it has never been easier to do that job in under ten minutes. Check your tax code at /check-my-tax-code before the current tax year runs any further. If your code is correct, you lose nothing. If it is wrong, the sooner you know, the sooner HMRC starts correcting its deductions and the smaller your eventual refund claim needs to be.

You started reading this article because you could not find your tax code. Now you know it is in five places, you know what it should probably say, and you know what to do if it does not. That thirty-second check you came here for can now happen. Go and do it.

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