Emergency tax codes explained: why your first payslip looks wrong
You start a new job, work your first week, and your payslip shows way less than you expected — sometimes dramatically less. Before you panic or assume you did your tax return wrong, it's worth knowing this is one of the most common, most normal things that happens when you start a job, and it's usually fixable in minutes.
What a tax code actually is
Every PAYE employee has a tax code, which tells your employer how much of your pay to treat as tax-free before working out Income Tax on the rest. The standard code for most people with one job and no special circumstances is currently 1257L — the "1257" refers to the £12,570 Personal Allowance (the amount you can earn tax-free each year), and the "L" means you get that allowance with no adjustments. This Personal Allowance has been frozen at £12,570 since 2021/22, and the freeze is currently set to run until April 2031, so you'll likely see 1257L for a while yet.
What an "emergency" tax code is
When your employer doesn't yet have your full pay history for the tax year — commonly because you're starting your first job, switching jobs without handing over a P45, or doing casual/seasonal work — HMRC can't apply your Personal Allowance normally. Instead, you might be put on an emergency basis, which can show up on your payslip as something like 1257L W1, 1257L M1, or sometimes just 0T or BR.
In plain terms: instead of spreading your tax-free allowance evenly across the year, an emergency code often taxes each payslip as if it were the only one you'll ever get, which can mean more tax is taken than you'll actually owe for the year as a whole. "W1" and "M1" mean "week 1" or "month 1" basis — each payday is treated in isolation rather than cumulatively.
If you've never had a job before, or you didn't give your new employer a P45 from your last one, there's simply no record yet of what you've earned and been taxed this tax year. HMRC and your employer fill that gap with a temporary code until the full picture catches up — which is exactly why it's so common for a first payslip, or a new term-time job, to look wrong.
How to check what's actually happening
The quickest way to see your real position is your free Personal Tax Account on gov.uk, or the HMRC app. Both show your current tax code, an estimate of your Income Tax for the year, and your income history. If HMRC's estimate shows you've paid too much, you can usually request a refund straight from there — directly into your bank account, at no cost.
How to fix it going forward
If you do have a P45 from a previous job, giving it to your new employer as soon as possible is the single best way to avoid an emergency code in the first place, since it hands over your pay and tax history for the year. If you don't have one — common for a first-ever job — your employer should ask you to complete a "starter checklist" instead, which gives HMRC enough information to correct your code, usually within a pay cycle or two.
How to get overpaid tax back
If you've already overpaid, you don't need to do anything complicated. Your Personal Tax Account will usually let you claim a refund directly once HMRC's figures confirm it. If you've stopped working entirely and aren't claiming benefits or starting straight into another job, form P50 on gov.uk is built for exactly that situation. You can generally claim back overpaid tax for the current tax year plus the previous four, so it's still worth checking even if the job in question ended a while ago.
If any of this sounds familiar — a part-time job, leaving work partway through the year, or just starting out — it's worth running our free checker to see what else might apply to you.
Check if you're owed a tax refund with Refund Checker →
Checking your tax code and claiming back overpaid tax through your Personal Tax Account is free and takes a few minutes. Be wary of any company offering to "recover your tax refund" for a cut of the money — you're paying for something you can do yourself for nothing.
A one-line version of all of this
An emergency tax code is a temporary placeholder, not a mistake you made — check your Personal Tax Account, hand over a P45 where you have one, and claim back anything overpaid directly through gov.uk, for free.