Yes, your tax code changes when you start getting the State Pension. HMRC treats the State Pension as taxable income, but the Department for Work and Pensions pays it to you without deducting any tax. To collect what you owe, HMRC reduces the tax-free allowance in the code applied to your other PAYE income — usually a workplace pension, private annuity, or part-time job — so more tax comes out of those payments instead.1Legislation.gov.uk. Income Tax (Earnings and Pensions) Act 2003 – Section 577
Why HMRC Has to Change the Code
The State Pension counts as taxable income under Section 577 of the Income Tax (Earnings and Pensions) Act 2003.1Legislation.gov.uk. Income Tax (Earnings and Pensions) Act 2003 – Section 577 If your total income from all sources goes over the Personal Allowance of £12,570, you owe tax on the amount above that threshold.
DWP does not operate PAYE on the State Pension. You receive the full amount with nothing withheld. HMRC has to collect any tax due through another channel, and your tax code is the tool it uses.
The squeeze matters more each year. The full new State Pension for 2026/27 is £241.30 a week, or roughly £12,548 a year — almost the entire £12,570 Personal Allowance.2GOV.UK. Proposed Benefit and Pension Rates 2026 to 2027 Even a small private pension or a bit of savings interest on top can now push you into paying tax.
How the New Code Is Worked Out
HMRC subtracts the annual value of your State Pension from your Personal Allowance. Whatever is left becomes the tax-free allowance assigned to your other income.
Say your State Pension is £11,502 a year. HMRC takes that off £12,570, leaving £1,068. Your tax code for a workplace pension or job would then read 106L instead of the standard 1257L. The number in the code is your remaining allowance divided by ten, and the “L” means you still qualify for the standard Personal Allowance.3GOV.UK. Tax Codes: What Your Tax Code Means Your pension provider or employer sees that lower code and withholds more tax from each payment, covering the tax due on both that income and your State Pension combined.
Your workplace pension or wages will therefore look smaller than you might expect after the change. If a private pension pays £6,000 a year and your code has absorbed most of your allowance to cover the State Pension, nearly all of that £6,000 gets taxed. The tax is not a separate charge on the State Pension. It is collected through the other income stream.
What the Letters on Your New Code Mean
The number tells your provider how much tax-free income to give you. The letter tells them which rules apply. The codes retirees see most often are:
- L — you still get the standard Personal Allowance. Most retirees with a reduced but positive allowance get an L code with a number below 1257.
- BR — all income from this pension or job is taxed at the basic rate. HMRC uses this when your entire Personal Allowance has already been allocated to a different income source.
- NT — no tax is deducted. This sometimes applies to the State Pension itself in HMRC’s records, since DWP pays it gross.
- K — your untaxed income is bigger than your Personal Allowance. Instead of sheltering some income from tax, a K code adds a notional amount to your taxable pay so extra tax comes out through each payment.3GOV.UK. Tax Codes: What Your Tax Code Means
The K code catches people out. If you get the full new State Pension of £12,548 plus taxable benefits like a company car or Incapacity Benefit that push your untaxed income past £12,570, HMRC cannot create a negative Personal Allowance. It issues a K code instead. A code of K50, for example, means £500 is added to your taxable income before your employer or pension provider works out the deduction.
If You Have No Other PAYE Income
The code adjustment only works if HMRC has another PAYE source to apply the code to. If the State Pension is your only income and it goes over the Personal Allowance, there is no code to change. HMRC sends you a Simple Assessment letter instead, calculating exactly what you owe.4GOV.UK. Pay Your Simple Assessment Tax Bill You do not file anything. HMRC does the sum using data it already holds from DWP and sends you the bill, which is due by 31 January following the end of the tax year.
If the State Pension is your only income and it falls below £12,570, you owe no tax at all. This is common for people on a reduced State Pension who did not build up the full 35 qualifying years of National Insurance. You get the pension gross, no code adjustment is needed, and there is nothing to pay.
Checking the New Code Is Right
Check your tax code through the “Check your Income Tax” service inside your Personal Tax Account on GOV.UK. It shows your current code, what HMRC thinks you earn from each source, and the estimated tax you will pay for the year. You can update income details directly if anything looks off.5GOV.UK. Check Your Income Tax for the Current Year
To see whether the code is accurate, compare the State Pension figure HMRC has used against the actual amount on your DWP pension letter. Errors happen most often in the first year of retirement, when HMRC may estimate your pension before DWP confirms the exact figure. A difference of even a few hundred pounds will skew your code and leave you over- or underpaying through the year.
If you spot a problem, update the figures online through the same service or call the Income Tax helpline. Have your DWP letter and any P60 forms from private pension providers to hand. After April each year, when State Pension rates typically go up, log back in to confirm HMRC has picked up the new amount.
If the Code Turns Out to Be Wrong
After the tax year ends, HMRC runs an automatic reconciliation to check whether you paid the right amount. If the numbers do not match — because your code was wrong, your income changed, or your State Pension amount was estimated incorrectly — HMRC sends you a P800 tax calculation letter. These go out between June and March of the following year.6GOV.UK. Tax Overpayments and Underpayments
If you overpaid, a P800 refund used to arrive automatically by cheque, but since May 2024 HMRC often requires you to claim the refund actively through your online account. If you do not claim it, you may not receive it. For refunds under £10, HMRC will only pay out on request. Read the P800 carefully for instructions.
If you underpaid, HMRC usually collects the shortfall by adjusting your code for the following year, spreading it across twelve months of payments rather than demanding a lump sum, provided the amount is under £3,000. For larger underpayments, HMRC may issue a Simple Assessment bill or ask for a direct payment.6GOV.UK. Tax Overpayments and Underpayments
Code errors in the first year or two of retirement are common enough to be almost expected. If your new code looks too low, or you were not expecting a K code, query it with HMRC before the year-end reconciliation. Catching it early keeps the adjustments small.