If you’re employed or receiving a pension in the UK, your tax code plays a vital role in determining how much tax is deducted from your income.
However, tax codes can sometimes be wrong, which may lead to overpaying or underpaying tax. In such cases, knowing how to contact HMRC about your tax code is essential.
Whether it’s via phone, app, post or webchat, there are clear steps you can follow to resolve any issues quickly and efficiently. This guide provides all the details you need to manage your tax code concerns directly with HMRC.
What Is a Tax Code and Why Does It Matter?
A tax code is a combination of letters and numbers assigned to you by HMRC to calculate how much Income Tax should be deducted from your earnings or pension.
Each code is based on your individual circumstances and takes into account your tax-free personal allowance, benefits, and other taxable income sources.
For instance, 1257L is the most common code, reflecting the standard personal allowance of £12,570. Other codes include letters like BR, D0, K, M, N, S, and T, which carry specific meanings.
- BR: All income is taxed at the basic rate (20%)
- D0: All income taxed at a higher rate (40%)
- K: Indicates untaxed income exceeding your allowance
- M/N: Related to Marriage Allowance transfers
- S/C: Taxed under Scottish or Welsh rates
- T: Code needs annual review by HMRC
Understanding your code ensures you pay the correct tax and helps avoid unexpected bills or refunds later.
How Can You Check If Your Tax Code Is Correct?
You should routinely check your tax code to ensure it reflects your current financial situation. Mistakes can occur if HMRC receives outdated or incorrect information, and the consequences can affect your take-home pay.
Here’s how you can verify your tax code:
- Check your most recent payslip (your code appears near your gross pay)
- Look at your P45 or P60 documents
- Review letters from HMRC regarding changes to your tax code
- Log in to your Personal Tax Account on the HMRC website
- Access the HMRC app and view the “Income Tax” section
- Contact HMRC directly for clarification
Regular checks help ensure you’re not paying too much or too little tax. If discrepancies are found, it’s vital to notify HMRC promptly.
What Are the Signs of a Wrong Tax Code?
It’s not always obvious that your tax code is incorrect. However, certain signs can indicate a possible issue. Spotting these early can prevent tax complications down the line.
A few key indicators of an incorrect tax code include:
- Unexpected changes in your take-home pay
- Receiving a P800 indicating underpayment or overpayment
- Emergency tax is being deducted when starting a new job
- Multiple job or pension sources are taxed incorrectly
- Letters from HMRC with unfamiliar codes
Common Tax Code Issues and What They Might Mean:
| Issue | Possible Cause |
| Sudden drop in salary | New or incorrect code like BR or D0 applied |
| P800 from HMRC | Tax underpaid or overpaid in the previous year |
| Code includes W1, M1 or X | Emergency tax code after job change |
| Code starts with K | Untaxed income exceeding personal allowance |
| Incorrect Marriage Allowance code | Unreported changes in marital status |
Identifying these signs early can help you avoid ongoing mistakes and financial issues.
How Can I View My Tax Code Online or in the HMRC App?
If you suspect an issue or want to check your tax code anytime, HMRC offers secure digital tools to make the process easier. You can view and manage your tax information using either the Personal Tax Account or the official HMRC app.
Here’s how you can access it:
- Log in to your Personal Tax Account using your Government Gateway ID
- Navigate to the Income Tax section
- View your current tax code, breakdown, and estimated annual tax
- Download the HMRC app from the App Store or Google Play
- After logging in, use the app to check your code, income history, and refund eligibility
Using these digital services helps avoid waiting on phone calls and gives you control over your tax affairs 24/7.
How to Contact HMRC About Tax Code?
When it comes to resolving tax code issues, HMRC provides several official contact methods. You can choose the one that best suits your situation and communication preferences.
If you need to speak directly to an advisor, phone is often the quickest route. However, online tools and postal services are also available.
HMRC Contact Options for Tax Code Queries
| Method | Details |
| Phone | Call 0300 200 3300 (UK) or +44 1355 359022 (outside UK) |
| Webchat | Use HMRC’s digital assistant with the option to speak to an advisor |
| App | Use the HMRC app to view and update tax code details |
| Post | Write to: HMRC, Pay As You Earn, BX9 1AS, United Kingdom |
| Relay UK | Dial 18001 then 0300 200 3300 for accessibility support |
Make sure to have your National Insurance number ready when you contact HMRC.
Is It Possible to Report Tax Code Issues Using the HMRC App?
Yes, HMRC’s official app allows you to handle several aspects of your tax code, including reporting problems or changes. It’s a fast and secure alternative to traditional contact methods.
Using the app, you can:
- Check your current tax code
- Update personal information
- View employment records
- Estimate how much tax you will pay for the year
However, for more complex issues, the app may redirect you to webchat or phone support. The app is most useful for straightforward queries and updates, especially when you’re unable to call during office hours.
What Personal Changes Should You Tell HMRC About to Avoid Wrong Tax Codes?
Keeping your personal information up to date is essential to ensure your tax code is correct. Any significant life or income change could affect how much tax you owe.
Marriage or Civil Partnership
If you get married or enter into a civil partnership, you might qualify for Marriage Allowance or need to update your personal tax details.
Change in Employment
Starting a new job, changing employers, or taking on a second job can impact your tax code. Always notify HMRC promptly about employment changes.
Benefits or Pensions
Receiving a new pension or taxable benefit should be reported. This includes state pension or workplace pensions and other taxable income.
Residency or Location Change
If you move between England, Scotland, or Wales, you may be taxed under different regional codes depending on your new residency.
By keeping HMRC informed, you reduce the risk of tax errors and future corrections.
What Should You Do If You’ve Paid Too Much or Too Little Tax?
If you discover you’ve paid an incorrect amount of tax, HMRC has procedures to help resolve it. In most cases, HMRC identifies discrepancies and issues a P800 tax calculation to explain whether you’ve overpaid or underpaid.
Overpaid tax:
- HMRC may automatically refund you through your salary.
- Alternatively, you can claim your refund online.
Underpaid tax:
- The underpayment may be spread across future payslips.
- HMRC may request a direct payment if the amount is large.
Check your Personal Tax Account:
- View current and past year tax estimates.
- Track the status of refunds or payments.
- Update your details to prevent repeated errors.
Quick tips to remember:
- Use your P800 notice to understand over/underpayment.
- Log into your Personal Tax Account for accurate updates.
- Contact HMRC if something looks incorrect.
- Always keep your payslips for verification.
By staying proactive and keeping your tax details up to date, you can avoid unexpected bills and ensure you pay the right amount of tax.
What If You Still Can’t Get Through to HMRC?
At times, reaching HMRC can feel frustrating, especially during busy periods with long wait times. However, there are alternative ways to get the help you need without relying solely on phone calls.
Practical alternatives to contacting HMRC
- Use Webchat: Start with the digital assistant, then request a live advisor if needed.
- Try off-peak hours: Call early morning or late evening, avoiding peak tax deadlines.
- Write a letter: Send your query to HMRC, BX9 1AS, UK, with your key details included.
- Use Relay UK: Dial 18001 before the helpline if you have hearing or speech difficulties.
By preparing documents and exploring all available channels, you can reduce delays and improve the chances of resolving your issue quickly.
Conclusion
Your tax code affects how much tax is taken from your pay, and getting it right is essential for financial accuracy. Whether it’s checking your code, updating personal details, or contacting HMRC for support, the process has become more accessible through digital tools and helplines.
Keep your records up to date and use official HMRC channels to resolve any issues quickly and securely.
Frequently Asked Questions
How long does it take HMRC to adjust a tax code after you contact them?
It usually takes HMRC up to four weeks to update your tax code after receiving all required information. You can check your personal tax account to track changes.
Can you claim a tax refund without contacting HMRC directly?
Yes, in many cases HMRC processes refunds automatically and deposits them to your bank. However, you can claim manually through your tax account if needed.
Are there specific tax codes that always require manual review?
Yes, codes like K, T, and emergency codes often require HMRC to manually verify income or deductions. These are typically reviewed annually or when flagged.
Is voice identification safe when speaking with HMRC?
HMRC uses secure voice recognition for faster identity verification. You can opt-in or out based on your comfort level with biometric data.
Can you use Relay UK or accessibility services to contact HMRC?
Yes, HMRC supports accessibility through Relay UK and other support services. This ensures everyone has equal access to tax services.
Does HMRC offer Welsh language support for tax code enquiries?
Yes, HMRC provides Welsh language services for Income Tax and PAYE queries. You can request this support when calling or writing.
Can you contact HMRC through social media for tax code queries?
You can use platforms like X to ask general questions, but never share personal details. HMRC cannot discuss specific tax matters on social platforms.
