Emergency Tax UK — How to Claim It Back
What emergency tax is, why it happens, how much you may be overpaying, and step-by-step instructions to get your money back.
What is emergency tax?
When HMRC does not have enough information about your income, your employer is instructed to use an emergency tax code. This happens most often when you start a new job without a P45, or when you begin your first ever job.
There are two main emergency tax codes:
- 20% deducted on all income
- No Personal Allowance applied
- Often used for second jobs or when HMRC has no data
- Leads to significant overpayment for most earners
- Full Personal Allowance applied (£12,570)
- But applied fresh each pay period
- Previous months not accounted for
- Can cause overpayment if you start mid-year
Why do I have an emergency tax code?
Common reasons:
- Started a new job without a P45 from your previous employer
- Starting your first ever job — no previous pay history with HMRC
- Returning to work after a long gap (e.g., maternity leave, career break)
- Being on a second job where HMRC does not know your first job income
- Your employer has not yet submitted your starter information to HMRC
- You have not completed the Starter Checklist your new employer gave you
How much will you overpay? — worked examples
Based on code BR (no Personal Allowance) vs correct code 1257L. Assumes this is your first month and no prior income in the tax year.
| Monthly gross | Tax at BR (20%) | Correct tax (1257L) | Monthly overpayment |
|---|---|---|---|
| £1,800 | £360 | £151 | £209 |
| £2,000 | £400 | £191 | £209 |
| £2,500 | £500 | £291 | £209 |
| £3,000 | £600 | £391 | £209 |
| £3,500 | £700 | £491 | £209 |
| £4,000 | £800 | £591 | £209 |
| £5,000 | £1,000 | £791 | £209 |
Example: If you earned £2,500 in a month on code BR, you paid £500 in tax. On the correct code 1257L, you would pay approximately £291. That is an overpayment of £209 — which you can reclaim.
These figures are approximate. Actual tax depends on prior income in the tax year, pension contributions, and other deductions. Use the salary calculator for a precise breakdown.
How to claim emergency tax back — step by step
If you are still employed at the same company
- Wait — HMRC usually sends the correct tax code to your employer within 1–3 payslips
- Your employer applies the new code and any overpayment is refunded in your next pay
- If it has not resolved after 3 months, log in to your HMRC Personal Tax Account to check and update your code
If you have stopped working (no new job)
- Complete form P50Z — claim tax refund when you have stopped working
- Download it from gov.uk or request from HMRC
- Submit it along with your P45 (if you have one)
- HMRC will process within 2–8 weeks and refund by bank transfer or cheque
If you are leaving the UK
- Complete form P85 — leaving the UK and stopping work
- HMRC will calculate any overpayment for the tax year and refund it
- Keep a UK bank account open if possible for the refund transfer
Contact HMRC directly
Call 0300 200 3300 (Monday to Friday, 8am–6pm). Have your National Insurance number, tax code, and most recent payslip ready. HMRC can update your code immediately and arrange a refund.
How long does it take to fix emergency tax?
In most cases, emergency tax resolves itself within 1–3 payslips. Once your employer submits your starter information through the RTI (Real Time Information) payroll system, HMRC processes it and issues an updated tax code. Your employer is legally required to apply new codes from the date they receive them.
If you have been on emergency tax for more than 3 months without resolution, the most common cause is that your employer has not submitted your starter details, or that HMRC is waiting on information. Contact HMRC directly to get this resolved — do not wait until the end of the year.
Will I get my overpaid tax back automatically?
If you remain employed with the same employer and they receive the correct tax code, yes — the refund comes through your payroll automatically. HMRC instructs your employer to apply a "cumulative" code, which recalculates your tax for the whole year and adjusts your next pay accordingly.
If you have left the job or stopped working, you need to claim manually (using P50Z or through your Personal Tax Account). HMRC does not automatically send refunds when you have left employment.
Frequently asked questions
What is emergency tax in the UK?
Emergency tax is applied when HMRC lacks information about your income. The main codes are BR (20% on all income, no allowance) and 1257L W1/M1 (full allowance but applied monthly without carry-forward). Both can lead to overpayment.
Why do I have an emergency tax code?
Most commonly because you started a new job without giving your employer a P45, or you are starting your first job. It can also happen if you are returning to work after a break or taking on a second job.
How do I claim emergency tax back?
If still employed: wait for HMRC to send the correct code — refund comes through payroll. If you have left work: use form P50Z. If leaving the UK: form P85. Or contact HMRC directly on 0300 200 3300.
What is the difference between BR and 1257L W1/M1 emergency tax?
BR is more severe — 20% on everything with no Personal Allowance. 1257L W1/M1 gives you the allowance but applies it per pay period without looking back at previous months. BR leads to higher overpayments.
How long does emergency tax last?
Usually 1 to 3 payslips after your employer submits your starter details. If it persists beyond 3 months, contact HMRC on 0300 200 3300.
How much emergency tax will I get back?
On code BR, roughly £200–£800+ per month depending on your salary. On 1257L W1/M1, the overpayment is smaller. See the worked examples table above for estimates based on your monthly pay.