Emergency Tax: Check Your Code and Refund Route

Emergency tax means PAYE is calculated for the current pay period without using your earlier pay and tax in the year. A W1, M1 or X marker identifies this non-cumulative treatment.

With 1257L M1, payroll gives one month's share of the allowance and bands, not a full year's allowance. Cumulative 1257L instead uses the allowance and bands available up to that point in the tax year, then deducts tax already paid.

Emergency treatment does not automatically mean an overpayment. With steady earnings, the two calculations can be very similar. Gaps in work, earlier earnings or a large commission payment can produce a difference in either direction. See the calculation-basis guide for the information needed to compare them.

Temporary treatment can follow a new job, a return to employment or a delay in matching your payroll records. Give payroll your P45 if available, or complete the starter checklist accurately.

A missing P45 does not always lead to emergency tax: the starter declaration and HMRC instructions determine which code and basis payroll should use. If HMRC has issued a code, ask payroll whether it has received and applied that notice.

Read the whole code, including its basis marker. BR and 0T without a marker are not, by themselves, proof of emergency treatment or an error.

These unprefixed rates describe England and Northern Ireland; Wales uses C-prefixed equivalents. Scottish S-prefixed codes can use different rates. Check HMRC's emergency-code guidance and your coding notice.

Assume £30,000 annual salary, £2,500 every month, England in 2026/27, standard allowance, no pension or other adjustments, and a job change in October (month 7). The previous employer paid £15,000 in months 1–6 and deducted £1,743 tax under these simplified assumptions.

The steady-pay example shows why an emergency marker alone does not prove extra tax. Actual PAYE can differ slightly because payroll uses code allowances and period rounding.

Assume steady pay throughout 2026/27 in England, full standard allowance entitlement, no pension or other adjustments and correct earlier tax. Monthly gross is approximately £2,083.33. These are annual tax amounts divided by 12, not exact payslip forecasts.

At this salary, BR and 0T both tax all the earnings at 20%. Whether the difference is an actual overpayment depends on your allowance entitlement, other income and earlier pay and tax. A second job may correctly have no allowance.

Assume steady pay throughout 2026/27 in England, full standard allowance entitlement, no pension or other adjustments and correct earlier tax. Monthly gross is approximately £3,333.33. These are annual tax amounts divided by 12, not exact payslip forecasts.

With 0T, £2,300 of annual pay exceeds the £37,700 basic-rate band, giving £8,460 annual tax (£705 monthly equivalent). BR stays at 20% on all £40,000. Whether the difference is an actual overpayment depends on your allowance entitlement, other income and earlier pay and tax. A second job may correctly have no allowance.

There is no fixed number of payslips. HMRC needs the right employment information and payroll must apply the resulting code and basis. Payroll cut-off dates affect when a change appears.

For a new job, HMRC says to allow 35 days from starting for the new employment details to be received. If the code is still wrong after that, use your personal tax account or contact HMRC. Give missing starter information to payroll promptly rather than waiting for that period to end.

A corrected cumulative code and complete year-to-date records may produce an in-year adjustment. A non-cumulative code does not itself recalculate earlier periods; other refund routes may be needed.

• Give payroll your P45, or complete the starter checklist if you do not have one.
• Check HMRC's employment record, estimated income and tax code in your personal tax account.
• Ask payroll which code and basis it received, and when the notice will be applied.
• If a new-job code is still wrong after 35 days, follow HMRC's new-job guidance.
• Keep earlier payslips and pay-to-date and tax-to-date figures. These are needed to assess a cumulative adjustment.

The right refund route depends on whether you are still working, the tax year and whether you use Self Assessment.

1. Employer corrects mid-year via payroll

Once payroll has the correct cumulative code and pay history, it can recalculate your tax for the year to date. A correction may reduce the next deduction or appear as a tax refund. Ask payroll which pay run will include it.

2. HMRC issues a P800 after the year end

HMRC checks PAYE after the year ends. Tax calculation letters are sent between June and March of the following tax year. Follow the instructions on your P800: online claims are normally paid within 5 working days; if the letter says an automatic cheque will be sent, it should arrive within 14 days. If you are registered for Self Assessment, overpayments are handled through that account instead.

3. Claim after stopping work

You may be able to claim in the current tax year using HMRC's P50 service. Eligibility depends on your circumstances, including later work, taxable benefits and pensions. Use HMRC's refund checker to find the appropriate route if you have no P800 or are unsure.