- The 0T tax code means HMRC is applying no Personal Allowance, so every pound of your income is taxed at the basic, higher or additional rate from the first pound earned.
- The most common triggers are starting a new job without a P45, having multiple income sources that use up your allowance elsewhere, or earning over £125,140 where the Personal Allowance is fully withdrawn.
- 0T is usually temporary: once you give your employer a P45 or starter checklist and HMRC updates your record, your code is corrected and any overpaid tax is refunded automatically.
What it means: No Personal Allowance applied, tax from the first pound earned
Allowance lost: £12,570 (the standard 2025/26 Personal Allowance)
Tax rates applied: 20%, 40% or 45% depending on your earnings
Most common trigger: Starting a new job without handing in a P45
High-earner threshold: Allowance fully withdrawn above £125,140
Is it permanent: No, usually corrected within 1 to 3 pay periods
How to fix it: Give your employer a P45 or starter checklist, then check your HMRC Personal Tax Account
Tax code 0T on your payslip means HMRC isn’t applying your £12,570 Personal Allowance, so every pound you earn is taxed at your normal rate from the very first pound. Depending on your salary, that’s a 20%, 40% or 45% deduction on income that would usually be tax-free, and on £30,000 of pay it costs around £2,514 extra a year until the code is corrected.
The 0T code usually appears when you start a new job without handing in a P45, when you have multiple income sources that use up your allowance elsewhere, or when you earn over £125,140 where the Personal Allowance is fully withdrawn. It’s almost always temporary. Once HMRC has the right information, your code is corrected and any overpaid tax is refunded.
This guide explains what 0T means, why it shows up, how it affects your take-home, and the exact steps to fix it. If you’d rather hand it off, our accounting services will sort the code and recover any overpaid tax.
Stuck on 0T and watching your take-home pay crash with no idea why?
What does the 0T tax code mean?
The 0T tax code means you don’t get a tax-free Personal Allowance through this job, so every pound you earn is taxed.
Typically, most employees get a £12,570 allowance spread evenly across the tax year. If you’re on 0T, none of that allowance applies, so your full income is taxed at your usual rate.
You might first notice this on your payslip or in your P60.
It’s worth checking your details through your HMRC Personal Tax Account to see which code is currently in use.
When HMRC applies the 0T code
HMRC uses 0T when they don’t have full or up-to-date information about your income. Common reasons include:
- Starting a new job without giving your employer your P45 or a completed Starter Checklist (P46)
- Switching jobs mid-year while still on the old tax code
- Having multiple jobs or pensions using your allowance elsewhere
- Earning above £125,140, when your Personal Allowance is completely withdrawn
If you’re not sure which applies, ask your employer or check your coding notice online.
If your pay or benefits change mid-year, review your code again after your next payslip to make sure HMRC has adjusted it correctly.
See our guide on Tax on a Second Job for more information about how all this works in practice.
How does 0T affect your income tax?
With the 0T tax code, you pay tax on your full income from that job without any Personal Allowance deducted first. The rate you pay depends on which band your income falls into.
Tax bands under the 0T code
Band | Income range (2024/25) | Tax rate under 0T |
Basic rate | Up to £37,700 | 20% |
Higher rate | £37,701–£125,140 | 40% |
Additional rate | Over £125,140 | 45% |
Under 0T, your full salary is taxed without any Personal Allowance applied first. Basic rate of 20% applies on income up to £37,700, higher rate of 40% on income from £37,701 to £125,140, and additional rate of 45% on anything above £125,140. Scottish rates differ slightly.
In practice, this means you’ll likely see a higher deduction on your payslip until your code is corrected.
For example, if you earn £40,000 a year and you’re on 0T, you’ll pay tax on the entire £40,000 instead of £27,430 (which is £40,000 minus the £12,570 allowance).
Scotland has different income tax bands, where rates range from 19% up to 47%. If you’re based there, your 0T deductions will follow Scottish thresholds.
If your pay or benefits change mid-year, review your code again after your next payslip to make sure HMRC has adjusted it correctly.
How do you fix the 0T tax code?
If you’ve spotted the 0T tax code on your payslip, don’t panic, it’s usually temporary and easy to fix. The key is making sure both your employer and HMRC have accurate information about your employment history and income.
Step 1. Give your employer the right documents
Provide your new employer with your P45 from your previous job. If you don’t have one, fill in HMRC’s Starter Checklist (P46) so they can apply the correct tax code.
You can also check your P45 vs P60 guide to understand the difference and why these forms matter for PAYE accuracy.
Step 2. Check your code with HMRC
Log in to your HMRC Personal Tax Account to confirm which tax code is active. If 0T is wrong, you can update your employment details directly online.
HMRC will usually send a new coding notice to both you and your employer within a few days.
Step 3. Look for the update on your payslip
Once corrected, the new tax code will appear on your next monthly payslip or within three weekly pay runs. You can review your National Insurance and tax deductions there to confirm everything’s aligned.
Step 4. Reclaim any overpaid tax
If you’ve paid too much under the 0T code, HMRC will usually refund you automatically through payroll. If not, you can claim a tax refund online using your National Insurance number and recent payslips.
What’s the difference between 0T and other tax codes?
Understanding how the 0T tax code compares with other common PAYE codes helps you check whether you’re being taxed correctly.
0T vs BR tax code
Both 0T and BR remove your Personal Allowance, but they work differently.
- BR taxes all your income at a flat 20%, no matter how much you earn.
- 0T taxes your full income at your marginal rate—20%, 40%, or 45%—depending on your total earnings.
If you’ve got a second job or pension, you might see BR appear there instead of 0T. Read more in our guide on tax for a second job.
0T vs W1/M1 emergency tax codes
Emergency codes like W1 (week 1) or M1 (month 1) are temporary. They give you a Personal Allowance for each pay period, but not cumulatively across the year. The 0T code gives no allowance at all.
Once HMRC receives your full employment details, these codes should be updated automatically.
0T vs 1257L
1257L is the standard code for most UK employees and includes the full £12,570 allowance. If you’re on 0T instead, you’re missing that allowance; so your tax bill will be higher until corrected.
How do you monitor and update your tax code?
Keeping an eye on your tax code helps you avoid surprise deductions or underpayments later in the year.
Check your payslip regularly
Each payslip shows your current tax code and National Insurance contributions. Compare this with the code listed in your HMRC Personal Tax Account. If the codes don’t match, contact HMRC or your employer’s payroll team.
If you’re self-employed as well as employed, review how income from both roles interacts. Our guide on tax obligations when running a business while employed explains how PAYE and Self Assessment can overlap.
Tell HMRC about life or job changes
Update HMRC whenever something changes that could affect your code, such as:
- starting or leaving a job
- receiving a new benefit in kind
- changes to working hours or salary
- getting married or claiming marriage allowance
You can make these updates online or through the HMRC app.
Keep your paperwork organised
Hold on to documents like your P45, P60, and National Insurance number. Having these ready makes fixing a tax code issue much quicker.
When should you get a tax accountant involved?
You don’t have to fix the 0T code on your own. A qualified tax accountant can make sure your PAYE, allowances, and HMRC details are correct.
Reviewing your tax position
An accountant can check whether 0T was applied correctly, review past payslips, and calculate if you’ve overpaid. If your employer made an error, they can coordinate with payroll to get it corrected.
If you’re also a company director, your accountant can ensure that your salary, dividends, and any s455 tax obligations are reported correctly. This keeps your overall tax efficient and prevents double taxation.
Communicating with HMRC
Tax accountants deal with HMRC every day, so they can handle code updates or refund claims for you. They’ll make sure your P45 or P60 data matches HMRC’s records and follow up if delays occur.
Recovering overpaid tax
If the 0T code led to overpayments, your accountant can submit a reclaim or ensure HMRC processes the refund through payroll.
What are the common misconceptions about 0T?
It’s easy to misunderstand what the 0T tax code means. Here are a few myths worth clearing up.
“0T is an emergency tax code”
It isn’t. Emergency codes usually end in W1, M1, or X and still include some Personal Allowance for each pay period. The 0T code applies no allowance at all and can tax you at higher rates until HMRC updates your record.
“You’ll lose money permanently if you’re on 0T”
You won’t. Any tax you overpay while on 0T is refunded once your code is corrected. HMRC will usually do this automatically through your employer or as a direct payment.
“Self-employed people can get the 0T tax code”
No. The 0T code only applies to PAYE employees. If you’re self-employed, you’ll pay tax through a Self Assessment tax return instead.
“The 0T code is permanent”
It’s temporary in most cases. Once HMRC receives the right details, it updates your record and restores your Personal Allowance.
How can you prevent future tax code issues?
Once your 0T tax code is corrected, a few simple checks can stop it from reappearing.
- Give your new employer your P45 or complete the Starter Checklist if you don’t have one. This ensures the right code is used from your first payslip.
- Keep your HMRC Personal Tax Account up to date. Check your income, benefits, and address regularly to avoid coding delays.
- Tell payroll about any changes in salary, hours, or taxable benefits as soon as they happen.
- Check your PAYE deductions with your National Insurance guide to confirm everything aligns.
- If you’re a director, make sure your salary is reported properly through PAYE. See our guide on trading vs non-trading for Corporation Tax.
- Review your tax code each April using the tax year dates guide to catch any errors early.
How Sleek helps fix your 0T tax code
When your payslip shows the 0T tax code, something in your PAYE record or HMRC data isn’t matching up. Sleek’s accountants find and fix the root cause by reviewing your payroll setup, employment history, and coding notice.
We’ll contact HMRC directly, correct your tax code, and recover any overpaid tax for you. Once everything’s aligned, your future payslips will stay accurate, and any job or income changes will automatically update with HMRC.
Disclaimer: The preceding information is not legal advice. This content is aimed to provide general guidance. For more formal or legal advice, contact Sleek directly.
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FAQs on tax code 0T
Why have I been given the 0T tax code?
HMRC applies 0T when they don’t have full information about your income, your Personal Allowance is used elsewhere, or you earn over £125,140 where the allowance is fully withdrawn. The most common trigger is starting a new job without giving your employer a P45 or completing a starter checklist on time.
How long does the 0T tax code usually last?
0T is normally temporary and corrected within one to three pay periods once HMRC has accurate information. If you’ve given your employer a P45 or starter checklist, the new code typically appears on your next monthly payslip. If 0T persists beyond two months without explanation, contact HMRC directly to investigate.
How much extra tax will I pay on 0T compared to 1257L?
On a £30,000 salary, 0T means paying tax on the full £30,000 instead of £17,430. That’s an extra £2,514 a year, or roughly £210 per month, until your code is corrected. The higher your salary, the bigger the gap, since you lose the full £12,570 Personal Allowance regardless.
Will I get an automatic refund if I’ve been on 0T?
Yes. HMRC usually refunds overpaid tax through your next payslip after your code is corrected, as long as the correction happens in the same tax year. If the tax year has ended, HMRC issues a P800 letter and refunds you directly. Refunds typically arrive within 30 days of the P800.
Is 0T worse than the BR tax code?
It can be. BR applies a flat 20% to all income, while 0T applies your marginal rate, which can be 20%, 40% or 45%. For high earners, 0T results in much higher deductions because more of your income falls into the higher or additional bands. For basic-rate earners, the two are similar.
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Can I be on 0T for one job but a normal code for another?
Yes. If you have multiple jobs or pensions, HMRC usually allocates your Personal Allowance to your main income source. The secondary job often gets a 0T or BR code because no allowance is left to apply. You can ask HMRC to split your allowance across jobs if it would result in lower overall tax.
What should I do if 0T hasn’t been corrected after several months?
First, log into your HMRC Personal Tax Account to check the code on record. If it still shows 0T, call HMRC on 0300 200 3300 with your National Insurance number and payslip. If your employer is using the wrong code despite HMRC issuing a new one, speak to your payroll team directly.
