Put on Emergency Tax at a New Job? Here's How to Fix It Fast

Starting a new job and suddenly losing 20–40% of your pay to emergency tax? You're not alone. Here's exactly what to do to fix it within days and reclaim what you've lost.

11 June 2026·5 min read

Emergency tax is one of the most common PAYE surprises in the UK — and one of the most fixable. It happens whenever HMRC doesn't have enough information about your circumstances to assign you a proper tax code. Here's the complete guide to getting it sorted.

What Is Emergency Tax?

When your employer doesn't have your P45 from your previous job, HMRC instructs them to use an emergency code. The most common emergency codes are:

BR: All income taxed at 20% from the first pound — no personal allowance
0T: No personal allowance, but the full range of rates apply (20%, 40%, 45%)
1257L W1/M1: Personal allowance applied, but on a non-cumulative "week 1/month 1" basis, which can still cause over- or under-payment

Why Does It Happen?

You didn't get or didn't hand over your P45 when you left your previous job
You started your first ever job
You were out of work for a period and HMRC doesn't know your status
HMRC's records didn't update in time for the payroll run

How to Fix It

Speak to your payroll team: Tell them you're on emergency tax and ask if they've received a P45 from your previous employer or a tax code from HMRC.
Contact HMRC: Call 0300 200 3300 or log into gov.uk/personal-tax-account and tell them you've started a new job. Confirm your NI number, previous employment details, and whether you have a P45.
Submit a starter checklist: If you don't have a P45, complete HMRC's "new employee starter checklist" (P46 equivalent) with your employer. This triggers HMRC to issue a proper code.

Getting the Money Back

Once the correct code is applied, PAYE is cumulative — meaning your employer's software will recalculate your tax-to-date for the whole tax year and refund any overpayment through reduced deductions in your next payslips. If you overpaid near the end of the tax year, HMRC will issue a P800 refund notice after 5 April.

Frequently Asked Questions

How long does emergency tax last?

Legally, it should last only until HMRC has enough information to assign a proper code — typically days to weeks. In practice, if you don't actively chase it, emergency codes can persist for months.

I've been on emergency tax for 3 months. How much am I owed?

Use our Overpaying Tax Calculator — enter your gross salary and select your emergency tax code to estimate the monthly overpayment and annual refund potential.

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