Answers · UK 2025/26
Why am I on emergency tax UK?
You are usually put on an emergency tax code (1257L W1/M1, BR, or 0T) when HMRC does not have full information about your previous earnings — typically when you start a new job without a P45, take a pension lump sum, or have multiple jobs. It usually corrects automatically within a few pay periods.
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Common triggers: starting a new job and giving your employer a starter checklist instead of a P45; second job (gets BR code = flat 20%); first time taking flexible pension drawdown (often 0T month 1, deducting at all bands with no Personal Allowance); switching from self-employment to employment mid-year. Symptoms: a code ending W1, M1 or X means non-cumulative, taxing each pay period in isolation, so you do not benefit from unused Personal Allowance carried forward. The codes themselves: 1257L W1/M1 (uses full PA but only against that period), BR (basic rate, all earnings at 20%), 0T (no allowance), D0 (all at 40%), D1 (all at 45%). Fix: send the new employer your P45 if available, or log into your HMRC personal tax account and update employment details — HMRC will reissue a cumulative code. Any overpayment in-year is refunded automatically once the cumulative code arrives, or claimed back after 5 April via P800 or self-assessment. Pension lump sums often need a P55 or P53Z form to fast-track a refund.
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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.