How to Check Your Tax Code Online (2026/27 Guide)

Jade’s August payslip was £90 lighter than she’d worked out on the back of a rota sheet. She’s a care assistant in Sunderland who took on bank shifts at a second home in July, and that job’s pay just didn’t add up. A colleague in the staff room said four words: check your tax code. So Jade did, on her phone, before her bus turned up. Here’s how to check your tax code online in 2026, what you’re looking at, and what to do if it’s wrong.

Checking Your Tax Code at a Glance

Standard code for 2026/27	1257L, a tax-free Personal Allowance of £12,570
Where to check online	Check your Income Tax service on GOV.UK, or the HMRC app
Sign-in needed	Government Gateway user ID and password, or GOV.UK One Login for new individuals
On paper	Payslip, P60, P45, or a Tax Code Notice letter (P2)
Emergency codes	Codes ending W1, M1 or X; usually fixed within 35 days of starting a job
Time to fix a wrong code	HMRC issues the new code within 15 working days
HMRC helpline	0300 200 3300, Monday to Friday, 8am to 6pm

Key facts on checking a UK tax code online, correct as of August 2026.

What a Tax Code Is and Why It Moves Your Pay

Payslip paperwork and a calculator on a desk showing where a tax code appears — A tax code tells your employer how much tax to take.

Jade had never looked at the little code next to her National Insurance number. Most people haven’t. A tax code is HMRC’s instruction to your employer or pension provider on how much Income Tax to take from you. Each job or pension gets its own. For 2026/27 the standard code is still 1257L, a tax-free Personal Allowance of £12,570, and HMRC’s P9X guidance for employers confirms that for the whole UK. It has sat there since April 2021, and the November 2025 Budget froze it to April 2031. Jade’s first job carried 1257L. Her second showed BR, which taxes every pound at the basic rate, and that was the gap. The letters carry more than you’d think, so what your UK tax code actually means deserves a closer look.

The Quickest Check: Your Personal Tax Account on GOV.UK

Signing in to the personal tax account on a laptop at home — The Check your Income Tax service shows your code in minutes.

At the bus stop Jade searched “check income tax” and landed on the official Check your Income Tax service on GOV.UK. It covers 6 April 2026 to 5 April 2027, and once inside you see your tax code for each job, your Personal Allowance, your estimated income and the tax you’ll pay. If the code has changed, the same screen tells you why. You sign in with a Government Gateway user ID and password, or GOV.UK One Login if you’re a brand-new individual user, HMRC’s route for new customers since February 2026. Never done this? Set up a Government Gateway account first; HMRC may ask for a passport or driving licence. Some 19.7 million people use the personal tax account, and paperless alerts email you whenever the code moves.

Checking on the HMRC App

Checking a tax code in the HMRC app on a smartphone — The HMRC app shows your tax code after a PIN or fingerprint sign-in.

Her colleague Dean prefers the app, and he had a point. The HMRC app is free on the App Store and Google Play, and you sign in with your HMRC online services details, or create them in the app. After that first sign-in you get back in with a 6-digit PIN, your fingerprint or face recognition, so Dean finds his code faster than his payslip. The app shows your tax code, income and benefits, and your employment history for the previous 5 years. You can also claim a refund, track letters, update your address and choose electronic contact instead of post. HMRC counted 7.6 million app users in 2025/26. If the sign-in screen stumps you, recover a lost Government Gateway user ID before trying again.

Payslip, P60, P45 and the Tax Code Notice

An envelope and folded letter on a table like a P60, P45 or Tax Code Notice — Payslips, P60s, P45s and the P2 letter all carry your tax code.

Not everyone wants to sign in at a bus stop, so know the paper places too. Your payslip must show your tax code alongside gross pay, deductions and net pay. Your P60, which your employer must give you by 31 May, shows the tax paid on your salary for the year that ended on 5 April. A P45 arrives when you leave a job and carries your tax code, leaving date, and pay and tax so far; keep Part 1A and hand Parts 2 and 3 to the new employer. Then there’s the Tax Code Notice, form P2, HMRC’s letter explaining how it worked out a new code. Those letters need the right address, so change your address on UK government services when you move.

Reading the Code: Numbers, Letters and the K Twist

Printing blocks of numbers and letters like those in a UK tax code — The numbers show your allowance; the letters tell the rest.

Jade’s 1257L made sense once Dean explained the maths. HMRC takes your Personal Allowance, knocks off untaxed income or deductions such as company benefits, drops the final digit and adds a letter. GOV.UK’s example is £1,570 of medical insurance taken from £12,570, leaving £11,000 and a code of 1100L. L means the standard allowance. M and N show Marriage Allowance moving 10% between partners. BR taxes everything at the basic rate, D0 at the higher rate, 0T means the allowance is used up, and S or C means Scottish or Welsh rates. A K at the start means untaxed income, often a company car or the pension your State Pension forecast once predicted, is bigger than your allowance. Even then, an employer cannot take more than half your pre-tax pay.

Emergency Codes: W1, M1 and X

A handshake on the first day of a new job before an emergency tax code — New starters often begin on an emergency tax code.

Dean’s first payslip at the home read 1257L M1 and he panicked. A code ending W1, M1 or X, or showing NONCUM, is an emergency code. It taxes each week or month alone, as if you earned that amount all year, and GOV.UK’s emergency tax code page admits you may pay the wrong amount. New starters get one when the employer lacks your previous pay details, so hand over your P45, or fill in the starter checklist without one. HMRC usually sends the proper code within 35 days of you starting. Those triggered by a new company benefit or the State Pension last until 5 April. HMRC emails paperless users about code changes but never texts refund links, so ask yourself is that HMRC text a scam before tapping.

Telling HMRC Your Code Is Wrong

A woman on the phone at a kitchen table telling HMRC her tax code is wrong — The online service is quickest, but 0300 200 3300 also works.

Jade’s BR code was right for a second job, but say it hadn’t been. GOV.UK says a wrong code usually means HMRC holds wrong or missing information, and the online service is the quickest fix. Sign in to Check your Income Tax, go through your employment, pension, estimated income, company benefit and expenses details, and correct anything wrong or missing. Work expenses relief can be claimed there too. HMRC then tells you and your employer the new code within 15 working days; paid monthly, it shows on your next or following payslip, paid weekly, on your third. After a new job, wait 35 days before chasing. Can’t get in? Work through why Government Gateway isn’t working, or ring HMRC on 0300 200 3300, Monday to Friday, 8am to 6pm.

Refunds, Underpayments and What Happens Next

A woman holding a bank card and phone as a tax refund arrives — Online refund claims usually pay out within 5 working days.

The good news for anyone overtaxed is that the money usually comes back through your wages. Once HMRC has your income details and issues a new code, it asks your employer to refund the difference, normally when that code is first used. If HMRC only spots the error after the tax year ends, it sends a tax calculation letter, known as a P800, or a Simple Assessment letter, between June and March. Claim online with the letter’s reference and your National Insurance number and the money arrives within 5 working days; cheques take 6 weeks. If you’ve underpaid, HMRC adjusts your code to collect the shortfall over a year or more. Jade didn’t need any of that, but her mum did, and learning to claim a tax refund online with HMRC took one evening.

Where This Leaves You

Jade’s mystery £90 turned out to be the right tax on a second job, and finding out cost her five minutes at a bus stop. When you check your tax code online you’re reading the number that decides your take-home pay, and the personal tax account or HMRC app will show it, explain any change and let you correct it without a phone queue. Sign in this week, especially if you’ve changed jobs or added a second income since April.

Frequently Asked Questions

What is the standard tax code for 2026/27?

The standard code is 1257L, giving a tax-free Personal Allowance of £12,570 across the UK. HMRC’s P9X guidance also names it the emergency code.

How do I check my tax code without a payslip?

Sign in to the Check your Income Tax service on GOV.UK or open the HMRC app. Both show your current code and why it changed.

Why is my tax code BR on my second job?

BR means all pay from that job is taxed at the basic rate, because your Personal Allowance is already used by your main job or pension.

How long does it take HMRC to fix a wrong tax code?

Once you update your details online, HMRC tells you and your employer the new code within 15 working days, then it reaches your next payslip or two.

Do I get a refund automatically if my tax code was wrong?

Usually yes, through your pay once the new code is used. If HMRC spots it after the tax year, a P800 letter explains how to claim.

Disclaimer: This article is general information, not financial or tax advice. Tax codes depend on your personal circumstances, so always check the official GOV.UK pages or speak to HMRC before acting. Figures are correct as of August 2026.