What is Tax Code 0T? A Clear Guide for UK Employees
In this guide, we break down what the 0T tax code is, when it applies, how it affects your take-home pay, and what steps you can take to correct it.
What Does the 0T Tax Code Mean?
If you've spotted tax code 0T on your payslip, it's understandable to feel confused — or even alarmed. This emergency tax code often results in more tax being deducted than necessary, and understanding what it means is key to fixing the issue quickly.
The 0T tax code tells your employer that you’re not entitled to any personal allowance — the tax-free income most UK residents can earn each year. As a result, all your income is taxed from the first pound you earn, without applying the standard Personal Allowance (which is £12,570 for the 2025/26 tax year).
In essence, HMRC uses the 0T code as an emergency measure when they don’t have enough information to issue the correct tax code.
When is Tax Code 0T Used?
HMRC may assign you the 0T tax code in the following situations:
You’ve started a new job, and your employer hasn't received your P45 or a completed Starter Checklist.
You’ve returned to work after a break (e.g. retirement, career gap) without providing updated tax information.
You’ve already used your Personal Allowance with another job or pension, and this new income must be fully taxed.
You’ve reached or exceeded your tax-free allowance, especially if you have multiple sources of income.
In some cases, the 0T tax code may be applied on a Week 1/Month 1 basis, meaning each payslip is taxed in isolation without considering earlier income in the tax year.
How Much Tax Will I Pay on a 0T Code?
With the 0T code, all of your income is taxed based on the standard income tax bands, but with no tax-free threshold.
Here’s how it breaks down for England, Wales, and Northern Ireland for the 2025/26 tax year:
📊 Income Tax Rates on 0T Tax Code (2025/26)
| Tax Band | Annual Income Range | Tax Rate |
|---|---|---|
| Basic Rate | £0 – £37,700 | 20% |
| Higher Rate | £37,701 – £125,140 | 40% |
| Additional Rate | Over £125,140 | 45% |
💡 Example: If you earn £2,000 in a month and are on a 0T tax code, you’ll pay 20% tax on the full amount — that’s £400 deducted immediately.
What Should You Do If You’re On a 0T Tax Code?
Being on tax code 0T doesn’t always mean a mistake has been made, but it’s worth checking. Follow these steps:
Check your payslip for the 0T code.
Speak to your employer or payroll team to make sure they’ve received your P45 or you’ve completed a Starter Checklist.
Log into your HMRC Personal Tax Account to check your current tax code.
Contact HMRC directly on 0300 200 3300 if you believe the code is wrong or outdated.
👉 Once HMRC has the right information, they can issue a corrected tax code and any overpaid tax will usually be refunded through your next payslip.
Is 0T Tax Code Ever Correct?
Yes. There are times when 0T is correct — particularly if:
You’ve used your full Personal Allowance elsewhere (e.g. on a pension or other job).
You have additional income streams that push you into higher tax bands.
HMRC is waiting for information before calculating a full-year tax profile.
However, if this doesn’t apply to you, it’s best to act quickly to avoid being overtaxed.
Can You Claim a Refund After 0T Tax Code?
Yes, HMRC automatically refunds overpaid tax, typically in your next payslip after your code is corrected. If you’ve overpaid and the tax year ends before it’s resolved, you can:
Claim online via your HMRC Personal Tax Account.
Submit a P50 form (if you’ve stopped working).
Wait for a P800 tax calculation letter from HMRC.
Summary: Key Takeaways
Tax code 0T means you’re not receiving any Personal Allowance.
It usually applies when HMRC lacks complete income info.
You may be overpaying tax while this code is in place.
Fixing it is usually as simple as submitting a P45, Starter Checklist, or contacting HMRC.
Refunds are automatic once your code is corrected.
Frequently Asked Questions
What does 0T mean on a payslip?
It means HMRC believes you’ve used your Personal Allowance, so all your income is taxed from £1 upwards.
Is 0T a bad tax code?
Not necessarily. It can be a temporary measure, but it often leads to overpaid tax.
How do I fix a 0T tax code?
Submit your P45 or Starter Checklist to your employer, or contact HMRC.
Will I get a refund after being on 0T?
Yes, any overpaid tax is usually refunded once your tax code is corrected.