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Tax & Salary · 2025/26

Emergency Tax Refund Estimator

Starting a new job without a P45? Pulling a pension lump sum? HMRC often defaults to an emergency tax code (BR, 0T or 1257L W1/M1), over-taxing you until they catch up.

£

Basic Rate — flat 20%, no allowance

Likely refund (per month overpaid)

£210

Breakdown

  • Tax under emergency code
    £500
  • Tax under 1257L (normal)
    £291
  • Monthly overpayment
    £210

How we calculated your result

We compare tax under your emergency code against tax under the normal 1257L code. The monthly difference is what HMRC is over-collecting.

Official UK rules in simple English

  • BR: 20% flat tax, no personal allowance.
  • 0T: full bands, no personal allowance.
  • W1/M1 (Week 1/Month 1): non-cumulative — each pay period treated alone.
  • HMRC normally rebalances via PAYE within 1–3 months once they have the right code.

Common pitfalls to watch out for

  • ⚠ Pension lump sums always emergency-coded

    First pension drawdown uses 1257L M1 — almost always over-taxes large lump sums by thousands.

  • ⚠ Use forms P55 / P53Z / P50Z

    For pension overpayments, claim back immediately — don’t wait for end-of-year reconciliation.

  • ⚠ Update your tax code

    Once HMRC gets P45 details, code updates automatically. Otherwise call 0300 200 3300.

Frequently asked questions

How long until automatic refund?
Usually next paycheque once the cumulative code is applied — or after 5 April for the prior year.
Can I claim mid-year?
Yes — by phone or via your Personal Tax Account online.

Educational. Real figures depend on full PAYE history.

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