Why Has My Tax Code Changed from 1257L to 1185L? Complete Guide (2026/27)
Tax code changed to 1185L? Learn why HMRC reduces tax codes, what it means for your take-home pay, how to check if it's correct, and how to fix errors.
If your tax code has changed from 1257L to 1185L, you are likely concerned about paying more tax and receiving less take-home pay. This is a common experience, with many people searching for answers to this exact question each month.
Quick answer: A change from 1257L to 1185L means HMRC has reduced your tax-free personal allowance by £720, from £12,570 to £11,850. This typically happens when HMRC believes you owe unpaid tax, have taxable benefits, or receive other untaxed income. For a basic rate taxpayer, this means approximately £144 more tax per year, which works out to around £12 per month or £2.77 per week. The actual amount depends on your marginal tax rate and individual circumstances.
This comprehensive guide explains exactly why tax codes change from 1257L to 1185L, what it means for your pay, and how to fix incorrect tax codes.
For a full breakdown of your take-home pay, try our Income Tax Calculator. If you are unsure about your overall tax position, our how to check and correct your HMRC tax code guide covers the process in detail.
A change from 1257L to 1185L means your tax-free allowance has been reduced by £720. For a basic rate taxpayer, this means approximately £144 more tax per year. This usually happens due to underpaid tax, company benefits, or other untaxed income.
What Does Tax Code 1185L Mean
Your tax code tells your employer how much tax-free income you are entitled to before deductions begin. The number in your tax code, when multiplied by 10, gives you your tax-free personal allowance for the year.
At the time of writing, the standard tax code for 2026/27 is 1257L, which gives you a personal allowance of £12,570. The 1185L code means your personal allowance is £11,850. This is a reduction of £720 compared to the standard 1257L.
The letter L in both codes indicates that you are entitled to the standard tax-free personal allowance, but the number has been reduced. This means you will pay tax on the £720 of income that was previously tax-free. For a basic rate taxpayer, this results in approximately £144 more tax per year.
For more on how tax codes work, our 1257L tax code guide explains the most common code in detail.
1185L means your tax-free allowance is £11,850, reduced from £12,570. For a basic rate taxpayer, this means approximately £144 more tax per year. The L indicates you are still entitled to the standard allowance, just at a reduced amount.
Why Has My Tax Code Changed from 1257L to 1185L
HMRC reduces tax codes for specific reasons. Understanding these reasons helps you determine whether your new code is correct or whether you need to challenge it.
Underpaid Tax from Previous Years is the most common reason for tax code reductions. HMRC reviews your tax records annually and may discover that you paid too little tax in a previous year. Instead of demanding immediate payment, they collect the debt gradually through the PAYE system by reducing your tax code. HMRC reduces your tax-free allowance by an amount designed to collect the estimated unpaid tax through PAYE. For example, if you owed £144 in unpaid tax from a previous tax year, HMRC would reduce your allowance by £720 (the amount that, when taxed at 20%, collects £144).
Company Benefits and Benefits-in-Kind also trigger tax code reductions. If your employer provides taxable benefits such as a company car, private health insurance, gym membership, or interest-free loans, HMRC adjusts your tax code to collect the tax on those benefits. The reduction is based on the cash value of the benefit. Tax code adjustments often combine multiple coding items, so the final tax code may reflect several deductions rather than one benefit alone. For instance, a company car with a taxable benefit of £5,600 would reduce your code by 560 points, making your code significantly lower than 1185L.
Our company car tax calculator can help you understand how vehicle benefits affect your tax code.
State Pension is another common cause. The State Pension is taxable but paid without tax deducted, so HMRC reduces your work tax code to collect the tax on your pension income. At the time of writing, the full State Pension is approximately £11,975 per year. If you are still working and receiving the State Pension, your work tax code will be reduced to collect the tax on your pension income.
Other Untaxed Income such as rental income, investment income, or a second job can also lead to tax code reductions. HMRC tries to collect the right tax throughout the year rather than issuing a large bill at year-end, so they adjust your code to reflect your estimated total income.
HMRC Administrative Errors are more common than many people realise. Incorrect benefit values on P11D forms, outdated information from previous employers, system glitches after job changes, and miscalculated underpayments can all result in incorrect tax codes. If you suspect an error, it is worth investigating.
Our why HMRC changes tax codes mid-year guide explains the common triggers for code changes.
Common reasons for tax code reductions include underpaid tax from previous years, company benefits such as a company car, State Pension income, other untaxed income, and HMRC administrative errors. Each reason has specific conditions and may be correct or incorrect depending on your circumstances.
How Much Extra Tax Will I Pay with 1185L
The financial impact of a tax code change from 1257L to 1185L depends on your marginal tax rate. You lose £720 of tax-free allowance, which is taxed at your marginal rate. For most basic rate taxpayers, this means an extra £144 in tax per year.
On a monthly basis, this works out to approximately £12 less in your take-home pay. On a weekly basis, it is about £2.77 less. While this is not a huge amount, it can be frustrating if the reduction is unexpected or incorrect.
If you are a higher rate taxpayer, the impact would be greater because the lost allowance would be taxed at 40%, resulting in £288 more tax per year. If you are an additional rate taxpayer, the impact would be £324 more per year at 45%. The exact amount depends on your total income and marginal tax rate.
Use our Income Tax Calculator to see the exact impact on your take-home pay based on your salary and circumstances.
A basic rate taxpayer pays approximately £144 more tax per year with 1185L, which is £12 per month or £2.77 per week. Higher rate taxpayers pay £288 more, and additional rate taxpayers pay £324 more.
Is My 1185L Tax Code Correct
Many people wrongly assume tax code changes are always correct. Following these steps helps you verify whether your new code is accurate or whether you need to challenge it.
Check your HMRC online account. Log in to the GOV.UK website and navigate to the PAYE section to view your current tax code and the breakdown of how it was calculated. This shows the reason for your tax code change, including any underpayments being collected, listed benefits-in-kind, and other deductions applied.
Review your payslips. Check recent payslips for your tax code and the date it changed. Compare the tax deducted before and after the change, and look at your year-to-date totals to see if the deductions are consistent.
Check for P11D benefits. Review any benefits you receive from your employer, such as a company car, private medical insurance, or other perks. Verify that the values on your P11D form are correct and that any benefits that have ended have been removed.
Review your P2 coding notice. HMRC sends a P2 coding notice explaining changes to your tax code. The notice shows your new tax code, a breakdown of allowances, and deductions applied. It also explains the reason for the change, such as "underpaid tax from [year]" or "car benefit."
Calculate what your code should be. Start with the standard allowance of £12,570. Deduct any taxable benefits you receive, any underpaid tax being collected, and any other untaxed income estimates. If the resulting code does not match 1185L, investigate further.
For more on checking your tax code, our how to check your tax code online guide covers the process step by step.
To verify your 1185L code, check your HMRC online account for the breakdown, review your payslips, verify P11D benefits, check your P2 coding notice, and calculate what your code should be based on your circumstances.
How to Fix an Incorrect 1185L Tax Code
If your tax code is wrong, you can fix it through several methods. The fastest way is to update your details online through your HMRC account.
Update your HMRC online account. Log in to the GOV.UK website, select PAYE, then check your tax code. Click "Tell us about a change" and update any incorrect information, such as company benefits that have ended, second jobs that have stopped, or incorrect pension details. HMRC usually updates your code within 3 to 7 days, and the new code is sent to your employer automatically.
Contact HMRC by phone. Call the HMRC Income Tax helpline on 0300 200 3300. Have your National Insurance number, P60 from the last tax year, recent payslips, and details of the incorrect code issue ready. HMRC will review your file, explain the tax code change, correct errors immediately, and issue a new tax code to your employer.
Write to HMRC. For complex issues or disputes, you can write to HM Revenue and Customs at BX9 1AS, United Kingdom. Include your full name, address, National Insurance number, tax reference from your payslip, a detailed explanation of the error, and supporting documents such as P60, P11D, or payslips. Response times are typically 15 to 30 days.
Speak to your employer's payroll department. If employer errors are causing the issue, your employer can correct P11D benefit values, confirm your employment dates, verify salary and pension details, and submit corrected information to HMRC. Employers cannot change tax codes directly but can request corrections.
Wait for automatic correction. HMRC reviews all tax after 5 April and issues a P800 tax calculation between August and November. If you have overpaid, the refund is processed automatically. However, this means you overpay all year and wait months for a refund.
Our tax refund guide explains how to claim money back if you have overpaid.
You can fix an incorrect tax code by updating your HMRC online account, calling HMRC, writing to them, or speaking to your employer's payroll department. Online updates are fastest, typically taking 3 to 7 days.
Common Tax Code Change Scenarios Explained
Understanding common scenarios helps you identify whether your tax code change is correct or whether you need to challenge it.
Started a new job recently. When you start a new job, your new employer may place you on an emergency tax code such as 1257L M1. Later, HMRC may update your code to 1185L or another reduced code. This happens because HMRC combines information from both jobs and allocates allowances across employments. The second job typically receives a BR code with no allowance, while the primary job may have a reduced code to balance the overall tax position.
Received a company car. If your employer gave you a company car, they will submit a P11D form showing the benefit value. HMRC then adjusts your tax code to collect the tax on that benefit. Tax code adjustments often combine multiple coding items, so the final tax code may reflect several deductions rather than one benefit alone. For example, a company car with a taxable benefit of £650 would reduce your code from 1257L to 1192L. If your code changed to 1185L, there may be another deduction of £70 on top of the car benefit.
Pension lump sum withdrawal. If you withdrew a lump sum from your pension, your pension provider may have used an emergency tax code, leading to overpayment. Later, HMRC may change your work tax code to 1185L because their system assumes you will have regular pension withdrawals. If the withdrawal was a one-off, you can claim a refund and request that your work code be restored.
Multiple jobs. If you have more than one job, HMRC allocates your Personal Allowance to one job. The other job receives a BR or D0 code. Your main job may have a reduced code if your total income pushes you into a higher tax band or if HMRC is collecting tax on the second income.
State Pension started. When you reach State Pension age, you start receiving taxable pension income. Since the State Pension is paid without tax deducted, HMRC reduces your work tax code to collect the tax. This is usually correct and should be expected.
Common scenarios include starting a new job, receiving a company car, taking a pension withdrawal, having multiple jobs, or receiving State Pension. Each has specific tax implications that may result in a reduced code.
How to Prevent Future Tax Code Problems
Preventing tax code errors is easier than fixing them. Several simple habits can help you avoid future issues.
Keep HMRC updated. Inform HMRC when you change jobs, when benefits start or stop, when you receive pension income, or when your address changes. You can update your details through your HMRC online account, by phone, or through your employer.
Check your tax code every April. The new tax year starts on 6 April, and tax codes are updated for new allowances. Verify your code is correct and challenge errors immediately.
Provide your P45 to new employers immediately. Your P45 tells your new employer your year-to-date tax, which prevents emergency tax codes. If you do not have a P45, complete the Starter Checklist provided by your employer.
Review P11D benefits annually. Your employer submits P11D forms by 6 July each year. Check that the values are correct, that benefits that have ended are removed, and that new benefits are accurate. Contact your payroll department if you spot errors.
Monitor your HMRC online account. Check your account regularly to view your PAYE income, confirm tax deducted matches expectations, review code change notifications, and act quickly on errors.
Prevent future tax code problems by keeping HMRC updated, checking your code every April, providing your P45 to new employers, reviewing P11D benefits, and monitoring your HMRC online account.
Final Thoughts
A tax code change from 1257L to 1185L means your tax-free allowance has been reduced by £720. For a basic rate taxpayer, this means approximately £144 more tax per year. This typically happens due to underpaid tax, company benefits, State Pension, or other untaxed income.
Not all tax code changes are correct. HMRC makes mistakes, and it is worth verifying your code through your HMRC online account. If you find an error, you can fix it quickly online or by phone.
Prevent future issues by keeping HMRC updated, checking your code every April, providing P45s to new employers, and reviewing P11D benefits annually.
All information in this guide is based on official HMRC and GOV.UK sources. Readers should verify their tax code through their HMRC online account before making financial decisions, as individual circumstances vary and rules may change after publication.
Written by
Daniel Reed
Daniel Reed writes about PAYE, payslips, tax codes, workplace deductions and take-home pay in the UK.
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