Answers · UK 2025/26
What is the 0T emergency tax code and when is it used?
The 0T tax code gives you no personal allowance at all, so every pound of pay is taxed immediately at basic, higher and additional rates as your income rises through the bands. HMRC issues it when a new employer has no P45 or starter checklist information, or when your personal allowance has already been used up elsewhere.
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The 0T tax code is one of the emergency and special tax codes HMRC issues when an employer does not yet have enough information to calculate your tax correctly. Unlike the standard 1257L code, which gives you the full £12,570 personal allowance spread evenly across the year, 0T applies no personal allowance whatsoever -- income tax is charged from the very first pound you earn in that employment. Despite having no tax-free allowance, 0T is not a flat-rate code: it still applies the normal progressive bands, so pay is taxed at 20% up to the basic rate limit, 40% in the higher rate band and 45% in the additional rate band as cumulative earnings in that job rise through the year. 0T commonly appears in three situations. First, when you start a new job and do not provide a P45 from a previous employer and do not complete a new starter checklist, so your employer has no way to confirm your tax history and cannot safely assume you are entitled to the allowance. Second, when your total income across all sources already exceeds £125,140, at which point the personal allowance has been fully tapered away and 0T reflects that correctly. Third, on a week 1/month 1 non-cumulative basis if HMRC has told your employer to disregard your full-year tax history for now. If 0T is used incorrectly -- for example, because your employer never received your P45 -- you will usually overpay tax initially, but this self-corrects once HMRC issues the right code, or you can claim a refund directly from HMRC or via Self Assessment. Always provide your P45 or complete the starter checklist promptly with a new employer to avoid being placed on 0T unnecessarily. Use the take-home pay calculator to see how much tax an emergency code like 0T would take from your pay.
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This answer is informational only and does not constitute financial, tax or legal advice. Figures are for the 2025/26 UK tax year. See our methodology and sources.