UK Tax Codes Explained 2026/27 — What Your Code Means and How to Fix It

Understanding Your Tax Code UK — What the Numbers Mean

How to read your UK tax code and what it means. Common tax codes explained, how to check yours is right, and what to do if it's wrong.

Tax information is based on HMRC rules for the 2026/27 tax year. Tax rules can change — always verify current rates at GOV.UK. This is not tax advice. Consider consulting a qualified tax adviser for your personal situation.

For a comprehensive overview of income tax, see our Income Tax guide.

Your tax code determines how much tax is taken from your pay. Here’s what it means and how to check it’s correct.

What Is a Tax Code?

The Purpose

What It DoesDetails
Tells employerHow much tax to take
Reflects your allowancesPersonal Allowance and adjustments
Applied to payrollAutomatically deducted
Different for each jobIf you have multiple

Where You Find It

LocationDetails
PayslipUsually near tax information
P60Annual summary
P45When leaving a job
HMRC onlinePersonal Tax Account
Tax code noticeLetter from HMRC

How to Read a Tax Code

The Number Part

How It WorksExample
Multiply by 10Your tax-free amount
1257 = £12,570Standard Personal Allowance
1100 = £11,000Reduced allowance
500 = £5,000Much reduced allowance

Common Letters

LetterMeaning
LStandard Personal Allowance
MMarriage Allowance received
NMarriage Allowance transferred away
TAllowance includes other calculations
0TNo Personal Allowance
BRAll income taxed at basic rate (20%)
D0All income taxed at higher rate (40%)
D1All income taxed at additional rate (45%)
NTNo tax (tax-free income)
SScottish taxpayer
CWelsh taxpayer

Common Tax Codes Explained

1257L

MeaningDetails
WhatStandard code for most people
Tax-free£12,570 (1257 × 10)
Who gets itOne job, standard allowance
Should you have itIf straightforward situation

1257L M

MeaningDetails
WhatReceiving Marriage Allowance
Tax-free£13,830 (extra from spouse)
Who gets itSpouse transferred allowance to you

BR

MeaningDetails
WhatBasic Rate on everything
Tax-free£0
Who gets itSecond job (allowance used on first)
All incomeTaxed at 20%

D0

MeaningDetails
WhatHigher Rate on everything
Tax-free£0
Who gets itSecond job when earning enough
All incomeTaxed at 40%

0T

MeaningDetails
WhatNo allowance given
Tax-free£0
WhyHMRC doesn’t have info or allowance used
ResultTax on everything

K Code

MeaningDetails
WhatMore to tax than allowance
ExampleK500
WhyBenefits in kind exceed allowance
ResultExtra tax collected through PAYE

Examples

CodeTax-Free AmountTypical Reason
1257L£12,570Standard
1000L£10,000Benefits reducing allowance
BR£0Second job
S1257L£12,570Scottish taxpayer
K500Negative (owe £5,000 extra)High benefits in kind

How Your Code Is Calculated

Standard Calculation

StepExample
Start with Personal Allowance£12,570
Add any extra allowances+£0
Subtract benefits in kind-£2,000
Subtract underpaid tax-£500
Result£10,070
Code1007L

What Reduces Your Code

ReductionWhy
Company carTaxable benefit
Private medical insuranceTaxable benefit
Tax owed from previous yearCollected through code
State PensionIf also working
Other incomeBeing collected via code

What Increases Your Code

AdditionWhy
Marriage AllowanceReceiving spouse’s transfer
Blind Person’s AllowanceRegistered blind
Work expensesHMRC agreed reliefs

Checking Your Tax Code

Is Your Code Right?

CheckWhat to Look For
Number close to 1257If standard circumstances
Benefits in kindShould reflect actual extras
Previous year balancesShould be repaid by now
Marriage AllowanceIf claimed/receiving

Signs of a Wrong Code

SignPossible Problem
Much lower than 1257Incorrect reduction applied
BR on only jobAllowance misallocated
0T on only jobHMRC missing information
K code unexpectedlyBenefits overstated

How to Check

MethodDetails
HMRC onlinePersonal Tax Account shows breakdown
Tax code noticeLetter explaining calculation
Contact HMRCIf unclear

Fixing a Wrong Tax Code

Steps to Take

StepAction
1Log into Personal Tax Account
2Check the calculation breakdown
3Identify what’s wrong
4Update information online or call HMRC
5New code issued to employer

What HMRC Can Change

IssueSolution
Wrong benefits listedRemove/correct them
Allowance missingAdd it back
Wrong income estimatedCorrect it
Previous year errorAdjust and refund/collect

Getting a Refund

SituationWhat Happens
Overpaid this yearAdjusted in future pay
Overpaid previous yearsRefund by cheque or into salary
Large overpaymentApply for P800 refund

Multiple Jobs and Tax Codes

How It Works

JobTypical Code
Main job1257L (full allowance)
Second jobBR (no allowance)
Third jobBR (no allowance)

Splitting Your Allowance

OptionHow
Split between jobsRequest from HMRC
All on one jobStandard approach
Why splitIf income varies

Common Problems

ProblemSolution
Allowance on wrong jobContact HMRC
No allowance at allCheck Personal Tax Account
Paying too muchHMRC will reconcile at year end

Emergency Tax Code

What Is It?

FeatureDetails
When usedNew job, no P45
CodeOften 1257L W1 or M1
EffectMonth-by-month (no cumulative)
ResultMay overpay initially

How to Fix Emergency Tax

StepAction
1Give P45 to new employer
2Or complete Starter Checklist
3HMRC updates code
4Excess tax refunded in subsequent pay

Summary: Tax Code Quick Reference

Common Codes

CodeMeaning
1257LStandard — full allowance
BRBasic rate on everything
D0Higher rate on everything
0TNo allowance
KYou owe extra
S prefixScottish taxpayer
C prefixWelsh taxpayer

Action Checklist

ActionWhen
Check code on payslipEvery new code
Review Personal Tax AccountAt least annually
Query if number seems lowBelow 1000 unexpectedly
Update HMRCIf circumstances change
Keep P45For new employers

Your tax code directly affects your take-home pay. Understanding it helps you catch errors that could cost you money.

Sources

  1. HMRC — Tax codes