EMERGENCY TAX · 2026/27
Emergency tax calculator
Estimate what a temporary tax code could do to one month’s pay and compare it with 1257L.
Estimated monthly take-home
£2,376
- Estimated Income Tax
- £652
- Estimated employee NI
- £172
- Tax difference vs 1257L
- +£221
This annualises one month to illustrate the code. Week 1/Month 1 payroll can differ because each pay period is calculated independently.
SOURCES & REVIEW
Checked against official guidance
Last checked 14 July 2026 · Rule version GB-2026.27.1
GOV.UK: Emergency tax codes ↗GOV.UK: Check your Income Tax ↗COMMON QUESTIONS
Frequently asked questions
What does an emergency tax code look like?
Emergency treatment may show W1, M1 or X after a code. 0T can also be used when payroll lacks allowance information.
Will emergency tax be refunded automatically?
Payroll may correct it after HMRC supplies a cumulative code; otherwise HMRC may reconcile the year.