Getting hit with emergency tax means seeing much less in your pay packet than expected. It’s frustrating — but it’s usually temporary and any overpaid tax will be refunded.
What Is Emergency Tax?
Emergency tax is a temporary tax calculation used when:
- Your employer doesn’t have your tax code from HMRC
- HMRC doesn’t have full details about your employment
- You haven’t provided a P45 or starter checklist
Instead of your normal tax code (like 1257L), you’re put on an emergency code that often results in paying more tax than you should.
Emergency Tax Codes Explained
| Code | What It Means | Impact |
|---|---|---|
| 1257L W1 | Standard allowance, weekly non-cumulative | Each week calculated separately — may overtax |
| 1257L M1 | Standard allowance, monthly non-cumulative | Each month calculated separately — may overtax |
| 0T W1/M1 | No personal allowance, non-cumulative | Taxed from first pound — severe overtaxation |
| BR | Basic rate (20%) on all earnings | No personal allowance — second job code |
| D0 | Higher rate (40%) on all earnings | Used for additional jobs sometimes |
| 1257L X | Another emergency variant | Similar non-cumulative effect |
What Does W1/M1 Mean?
W1 (Week 1) or M1 (Month 1) means:
- Each pay period calculated in isolation
- Your annual allowance isn’t spread across the year
- Previous payslips have no effect on current calculation
Normal cumulative tax codes spread your £12,570 allowance across the year and consider previous pay periods.
Why You’re on Emergency Tax
1. New Job Without P45
The most common cause. If you didn’t give your employer your P45:
- They don’t know your previous earnings
- They don’t know your tax code
- HMRC hasn’t sent them a code yet
Solution: Give them your P45, or complete a starter checklist declaring your employment status.
2. Lost or No P45
If your previous employer didn’t give you a P45 (or you lost it):
- Request a replacement from your old employer
- Or complete a starter checklist for your new employer
- Tell HMRC via your Personal Tax Account
3. First Job Ever
If you’ve never worked before:
- No previous tax code exists
- Your employer needs HMRC to issue one
- This can take a few weeks
Complete a starter checklist and ensure you’re registered with HMRC.
4. Returning from Abroad
If you were working overseas and now have a UK job:
- HMRC doesn’t have recent UK employment records
- Your employer can’t verify your status
- Emergency tax applies until sorted
5. Pension Drawdown
Taking money from your pension can trigger emergency tax:
- First withdrawal often uses emergency code
- 75% of withdrawal may be taxed as income
- This applies the first time you access a new pension pot
6. Multiple Jobs
If HMRC doesn’t know about all your jobs:
- One job might get full allowance
- Others might be on BR or emergency codes
- Total tax may be wrong
How Much Extra Am I Paying?
Example: £30,000 Salary
| Tax Code | Monthly Tax Deduction | Difference from Normal |
|---|---|---|
| 1257L (correct) | ~£291 | — |
| 1257L M1 (emergency) | ~£350-400 | £60-110 extra |
| 0T M1 (emergency, no allowance) | ~£500 | £210 extra |
| BR (second job) | ~£500 | £210 extra |
Emergency tax can cost you £100-300 extra per month until resolved.
Example: £50,000 Salary
| Tax Code | Monthly Tax Deduction | Difference from Normal |
|---|---|---|
| 1257L (correct) | ~£630 | — |
| 1257L M1 (emergency) | ~£700-750 | £70-120 extra |
| 0T M1 (emergency, no allowance) | ~£833 | £200 extra |
How to Fix Emergency Tax
Step 1: Give Your Employer the Right Information
If you have a P45:
- Give Parts 2 and 3 to your new employer immediately
- They’ll use it to set your tax code
If you don’t have a P45:
- Complete a Starter Checklist (formerly P46)
- Your employer provides this form
- Choose the correct statement:
- A: This is my first job since 6 April
- B: This is my only job (not getting pension/benefits)
- C: I have another job or pension
Step 2: Contact HMRC
If emergency tax continues after 4-6 weeks:
- Log into Personal Tax Account at gov.uk/personal-tax-account
- Check your tax code and employment details
- Update any incorrect information
- Tell HMRC about your situation
Or call HMRC on 0300 200 3300 (Income Tax helpline).
Step 3: Wait for Your Employer to Receive New Code
HMRC sends your correct code directly to your employer. This typically takes:
- 2-4 weeks for online updates
- 4-6 weeks by post
Once received, your employer must adjust your tax immediately.
Getting Your Money Back
If Still in Same Tax Year
When your tax code is corrected, your employer should:
- Calculate what you should have paid cumulatively
- Refund the overpayment through your next payslip(s)
You may see a larger-than-usual net pay for one or two months.
If Tax Year Has Ended
HMRC sends P800 tax calculations after the tax year ends (usually by September). This shows:
- How much tax you paid
- How much you should have paid
- Any refund due
Refunds are usually paid automatically, or you can claim online.
Claim Online Now
If waiting for your employer or P800 is too slow:
- Log into Personal Tax Account
- Check your Income Tax for the year
- If overpaid, request a refund online
- Or call HMRC to request expedited refund
Emergency Tax on Pension Withdrawals
Taking money from a pension pot for the first time often triggers emergency tax:
How it works:
- Your pension provider doesn’t know your other income
- They apply emergency tax to the taxable portion (75%)
- You may pay too much
Example: £10,000 pension withdrawal
- £2,500 tax-free (25%)
- £7,500 taxable — emergency tax might take £1,500+
- Correct tax might only be £600 (basic rate)
Getting refund:
- Wait for HMRC P800 (automatic reconciliation)
- Or claim immediately using form P55 or P50Z
- Or claim via Personal Tax Account
Avoiding Emergency Tax
When Starting a New Job
- Get your P45 from previous employer on your last day
- Give Parts 2 and 3 to new employer immediately
- Complete starter checklist if no P45
- Check your payslip for correct tax code
- Query emergency codes immediately
When Taking Pension
- Consider small initial withdrawal to trigger code setup
- Wait for correct code before larger withdrawals
- Or accept emergency tax and claim refund after
Keep HMRC Updated
- Register for Personal Tax Account
- Update employment changes promptly
- Check tax code annually
Common Questions
“Can emergency tax be right?”
Occasionally, yes. If you genuinely have no allowance available (used elsewhere or high income), what looks like emergency tax might be correct. Check via Personal Tax Account.
“Can I refuse to pay emergency tax?”
No — your employer must use your tax code as HMRC instructs (or emergency code if none). You’ll get overpayments refunded later.
“How do I know I’m on emergency tax?”
Check your payslip for:
- Tax code ending in W1, M1, or X
- No standard allowance (0T)
- Higher-than-expected tax deduction
“Can my employer fix it?”
Your employer applies whatever code HMRC provides. They can’t unilaterally change it. You need to contact HMRC or provide correct documentation.
Related Guides
- Why Has My Tax Code Changed? — Understanding tax codes
- UK Income Tax Guide — How tax is calculated
- Personal Allowance Explained — Your tax-free amount
- PAYE Explained — How employers deduct tax
- How to Check Your Tax Code — Step by step
Emergency tax is annoying but temporary. Provide your P45 or starter checklist, check your Personal Tax Account, and any overpaid tax will be refunded. Don’t wait — the sooner you act, the sooner it’s fixed.