What Does Tax Code 0T Mean?

Tax code 0T means you get no tax-free Personal Allowance on that income, so tax is charged from the very first pound. Unlike a BR code, which taxes everything at 20%, a 0T code applies the normal tax bands as your income rises, so higher earnings can be taxed at 40% or 45%.

In this insight we explain what 0T means, the common reasons you might be given it, how it differs from other codes, and how to fix it if it is wrong.

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Key Takeaways

• 0T means no Personal Allowance is applied to that income, so tax starts from the first pound you earn from it.
• Unlike BR, which is a flat 20%, 0T uses the normal rates and bands, so higher earnings can be taxed at 40% or 45%.
• It often appears when HMRC has no details for a new job, your allowance is used up elsewhere, or your income is very high.
• If 0T is wrong for you, giving HMRC your details usually restores your allowance and triggers a refund of any overpaid tax.

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What 0T Means

A 0T tax code gives you no tax-free Personal Allowance against that source of income, and it taxes your earnings using the standard rates and bands. The zero reflects that there is no allowance attached to the code.

This is different from having the standard code, where the first £12,570 is tax-free for 2025/26. With 0T, every pound is potentially taxable, starting at 20% and moving up to 40% and 45% as your income grows, or the equivalent Scottish bands if you are a Scottish taxpayer with an S prefix.

For the bigger picture on how codes are structured, see our guide to tax codes explained.

Common Causes of a 0T Code

There are several reasons HMRC or your employer might apply a 0T code:

• You started a new job without a P45 and did not complete a starter checklist, so your employer has no allowance details to apply.
• Your Personal Allowance is already used up against another job or pension, so there is none left for this income.
• Your income is very high. The Personal Allowance is reduced for income above £100,000 and disappears entirely by £125,140, so high earners can end up on 0T.
• A previous employment was not closed off correctly in HMRC's records.

If your code recently switched to 0T, our guide to why your tax code has changed may help you pin down the reason.

0T Versus BR and Emergency Codes

It is easy to confuse 0T with other allowance-free codes, but there are important differences:

• 0T gives no allowance and applies the normal bands, so tax rises from 20% to 40% to 45% as income increases.
• BR gives no allowance but taxes everything at a flat 20%, regardless of how much you earn from that source.
• Emergency codes such as 1257L W1 often still give the standard allowance, but apply it on a non-cumulative basis.

The practical upshot is that 0T can take more tax than BR from a higher earner, because it does not cap the rate at 20%. You can compare what you should be paying with our income tax calculator.

Is 0T Right for You?

For many people, 0T is not the ideal code, because it means you are not getting your tax-free allowance against that income. It can be correct if your allowance is genuinely used up elsewhere, or if your income is high enough that you have lost the allowance.

But if 0T is on your only job and you should be receiving the full allowance, you are likely overpaying. This is worth checking promptly, especially if you have just changed jobs or started work for the first time. Understanding where your earnings sit can also help, and our look at what a good salary is in the UK offers useful context.

How to Fix a 0T Code

To get your allowance restored where you are entitled to it:

• Give your employer your P45 or complete the starter checklist so they can apply the correct code.
• Check your personal tax account on GOV.UK to see how your allowance is allocated.
• Contact HMRC to move your allowance to the right income or update your details.

Once corrected, HMRC normally refunds any tax you overpaid because of the 0T code, either through your pay or after the tax year ends. You can find more helpful tools on our calculators page.

Frequently asked questions

Why am I on a 0T tax code?

Common reasons are that you started a job without giving HMRC your details, your Personal Allowance is being used against another income, or you earn enough that your allowance has been reduced or removed. Checking your personal tax account usually shows which applies to you.

Is 0T worse than BR?

It depends on your income. Both give no allowance, but 0T uses the normal bands, so a higher earner could pay 40% or 45% on some of that income, whereas BR caps it at 20%. For a basic-rate taxpayer the difference may be small, but for higher earners 0T can take more.

Will my Personal Allowance come back?

If you are entitled to it, yes. Once HMRC has your details and allocates your allowance correctly, your code should change and your allowance will apply. Any overpaid tax is normally refunded. If your income is above £125,140, however, the allowance is not available at all.

How do I change a 0T code?

Provide your P45 or a completed starter checklist to your employer, and make sure HMRC has your full details through your personal tax account or by contacting them. HMRC will then issue the correct code to your employer, and your future pay will reflect it.

General information only, not financial advice. If you think your tax code is wrong, contact HMRC.