HM Revenue and Customs (HMRC) has issued guidance to UK taxpayers who have recently changed jobs and noticed an unexpected alteration in their tax code on their payslips. The clarification comes after individuals took to social media platform X, formerly Twitter, to query discrepancies.
Why Has My Tax Code Changed?
A concerned taxpayer highlighted the issue online, stating: "Today I noticed a difference in my tax code for the last financial year. In my previous job it was 1257L, but after joining my current organisation it changed to 1148L. Can anyone advise why this happens?"
In a direct response, HMRC provided a clear explanation. A change in your tax code can occur if you switch employment and the pay period from your final salary at your old job overlaps with the pay period from your first salary at the new position. This administrative overlap can temporarily affect how your tax-free Personal Allowance is allocated between employers.
How to Check and Update Your Details
HMRC urges all taxpayers to proactively manage their records using its online service. This digital tool allows you to:
- Check your current tax code and Personal Allowance.
- View estimated income from jobs and pensions and the tax you can expect to pay for the current tax year.
- Update details of your income from jobs and pensions. Out-of-date information is a common cause of paying too much or too little tax.
- See if your tax code has changed and inform HMRC about any changes affecting it.
- Update your employer or pension provider details.
It is important to note that you cannot use this service to check your Income Tax for the current year if Self Assessment is the only way you pay Income Tax.
Taking Action to Stay Correct
To access the service, you will need to sign in. If you do not have sign-in details, you can create them. HMRC may ask you to prove your identity to keep your details secure, which usually involves using a photo ID like a passport or driving licence.
Regularly reviewing your payslip and cross-referencing it with your online tax account is the best defence against incorrect tax deductions. If your circumstances change—such as starting a new job, receiving a company car, or getting a state pension—you must inform HMRC promptly to avoid future complications with your tax code.
