Started a new job and your first payslip looks horrifying? You're probably on emergency tax. Here's what's happening and how to fix it.
What Is Emergency Tax?
Emergency tax means your employer is calculating your tax on a non-cumulative basis (tax code ending in W1 or M1). Instead of spreading your annual personal allowance evenly across the year, they're treating each pay period in isolation. This usually means you're paying too much.
How much extra are you paying?
On a £30,000 salary, correct monthly tax is about £290. On emergency tax, you might pay £400-£500 depending on timing. That's up to £200/month too much.
Why It Happens
The most common reasons are starting a new job without giving your employer a P45 from your previous job, your first job ever (HMRC hasn't set up your tax record yet), or returning to work after a gap. Your employer doesn't know your tax history, so they use emergency rates as a safe default.
How to Fix It
Option 1 (fastest): Give your new employer your P45 from your previous job. They'll update your tax code immediately.
Option 2: If you don't have a P45, your employer should give you a Starter Checklist (formerly P46) to fill in. This triggers HMRC to issue the correct code.
Option 3: Call HMRC on 0300 200 3300 or use your Personal Tax Account online to update your employment details.
Will I Get My Money Back?
Yes. Once your correct tax code is applied, PAYE's cumulative system will automatically recalculate your tax for the year so far. Any overpayment will appear as a larger-than-usual take home in the next pay period. You don't need to file a claim — it happens automatically through your payroll.
Check what your take home should be
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