Emergency tax code reclaim

Why you are on an emergency tax code

An emergency tax code is almost never a sign that anything has gone wrong or that you are being penalised. It usually just means that when you were first paid, your employer did not have enough information about your income and tax history for the current tax year, so HMRC could not work out your correct code yet.

The most common triggers in a student job are:

1. You did not give your new employer a P45 from a previous job (for example because this is your first job, or your last employer never issued one).

2. You started work partway through the tax year, or you have more than one job, so your tax-free Personal Allowance had not yet been allocated to this employer.

3. You did not complete, or did not complete correctly, the HMRC starter checklist (the form that replaced the old P46). The answers on that checklist decide which starter code your employer uses.

Under an emergency code your tax is worked out only on what you are paid in that individual week or month, as if you earned that amount every pay period all year, rather than on your total income so far in the year. Emergency codes usually look like 1257L W1, 1257L M1 or 1257L X. There are also stricter starter codes, such as BR (all pay taxed at basic rate with no allowance, often used for a second job), 0T (no allowance at all), or D0. If you have been given BR or 0T, that is why deductions may look high even on modest earnings.

Why students often overpay

Income tax uses an annual Personal Allowance, which for 2024/25 and 2025/26 is £12,570. If your total earnings for the whole tax year stay below that figure, you should pay no income tax at all. Many students work only part of the year or only in the holidays, so they end up below the threshold overall.

The problem is that an emergency or month-1 code taxes each pay packet in isolation and does not spread your allowance properly across the year, so a large single payment or a burst of holiday work can be over-taxed even though your annual income is low. This is how overpayments happen. National Insurance works differently and is not refundable in the same way, so this generally only affects income tax.

Getting onto the correct code going forward

1. If you have a P45 from a previous job this tax year, give it to your current employer. This is the quickest way to get your correct code applied.

2. If you have no P45, complete the HMRC starter checklist accurately for your employer. For most students in a single job, the correct statement is that this is your only or main job and you have not had other taxable income, which should give you the standard 1257L allowance.

3. Check your Personal Tax Account or the HMRC app. You can view your current tax code, tell HMRC about your circumstances, and in many cases the code is corrected online. HMRC normally updates the code automatically once it receives details from your old and new employers, which can take up to 35 days from when you start.

Once the correct cumulative code is applied during the same tax year, your employer will often refund any overpaid tax automatically through your payslip in a later pay period, so you may not need to claim at all.

How to reclaim tax you have already overpaid

How you reclaim depends on your situation.

If you are still in the job and it is still the same tax year, the simplest route is usually to get the correct cumulative tax code applied, as above. When HMRC issues the corrected code to your employer, any overpayment for the year to date is normally repaid through your next payslip.

If you have stopped working or left the job partway through the year, you cannot rely on payroll to refund you. Keep the P45 your employer must give you when you leave. If you do not expect to work again before the end of the tax year (5 April), you can claim a refund using HMRC form P50, which lets you reclaim tax when you stop working and are not claiming certain benefits.

If the tax year has already ended, HMRC reconciles PAYE records after 5 April. If you overpaid, HMRC usually sends a P800 tax calculation or a Simple Assessment, often between around June and November. Where a refund is due you can frequently claim it online through your Personal Tax Account, and choose a bank transfer rather than waiting for a cheque. You can go back and claim for up to four earlier tax years if you missed a refund.

The GOV.UK tool at gov.uk/claim-tax-refund will ask a few questions and point you to the exact route and form for your circumstances, and gov.uk/tax-codes covers emergency codes specifically.

What you will need

Have these to hand, as they make any claim much faster and let you check the figures yourself:

1. Your National Insurance number.

2. Your payslips and any P45 or P60 showing pay and tax deducted.

3. The dates you worked and details of any other jobs in the same tax year.

4. Your Government Gateway login for the HMRC Personal Tax Account or app.

Watch points

Do not assume every high deduction is a mistake. A BR or 0T code is applied correctly in some situations, for example a genuine second job, and taxing that job in full can be right if your allowance is already used against your main job. Check your total position across all jobs rather than looking at one payslip in isolation.

Be cautious about third-party companies that offer to reclaim tax for you for a percentage fee. Claiming directly through HMRC is free, and the official channels above will handle a straightforward student overpayment without any charge.

If you are a student who also works abroad in vacations, or you are not UK-resident for tax, or you have savings or self-employed income as well, the position is more involved and the simple refund routes above may not fully apply. If any of that is the case, let me know the extra detail and I can tailor this.