UK pay and tax guides
35 plain answers to the questions a payslip raises, all worked from the same tested 2026/27 rules and linked to the official source. Nothing you type leaves your browser.
What do you want to understand?Tax codes
What does tax code 1257L mean?The most common tax code in the UK, explained in plain English: what the number and letter mean, when it’s wrong, and what to do about it.What does the BR tax code mean?Why a second job is taxed from the first pound, when that is the right answer, and the two situations in which a BR code takes the wrong amount.What does the 0T tax code mean?A 0T code gives you no tax-free pay at all. Here is why one is issued, what it costs against the standard code, and how the overpayment comes back.What do the D0 and D1 tax codes mean?Two flat codes for a second income, and the Scottish versions that do not mean what their names suggest.What is a K tax code?A K code adds to the pay your employer taxes instead of taking tax off it. What causes one, the limit that protects your payslip, and how to check it is right.What do the S and C in a tax code mean?The letter at the front of your code is a rate ladder, not an allowance. How HMRC decides which one applies, what it is worth, and what happens when you move.What are emergency tax codes (W1, M1, X)?W1, M1 and X mean each pay day is taxed on its own, with no memory of the rest of the year. Why that happens, what it costs, and how long it lasts.How to check your tax codeWhere your code lives, the arithmetic that says whether it is right, the six signs it is not, and how long a correction takes to reach your pay.
National Insurance
Student loans
Pensions
Salary sacrifice explainedWhat giving up salary for a pension contribution does to your tax, your National Insurance and your take-home pay, and the things it changes that are not about tax at all.Relief at source vs net payTwo ways a workplace pension collects the same contribution. They look identical on paper and different on a payslip, and for some people they are worth different amounts.
Allowances
Payslips
How to read your payslipEvery line on a payslip, in the order it appears, with a worked month so you can hold the two side by side.Why is my take-home different from the calculator?Nine reasons a real payslip misses a whole-year calculation, in the order they are worth checking, and how to tell which one is yours.How to get an emergency tax refundWhat comes back through payroll on its own, what has to wait for the year end, and what you have to ask for.
Pay
Is overtime taxed more?Extra hours are taxed at exactly the same rates as the rest of your pay. Here is why a payslip can still make them look punished, and what an hour of overtime is really worth.Is a bonus taxed more?A bonus is taxed as ordinary pay, and a bonus month still looks brutal on a payslip. Both of those are true, for different reasons.How tax on a second job worksOne Personal Allowance, two employers, and two systems that treat the pair in opposite ways. What the second job actually pays, and what to check.Will a pay rise push me into the 40% band?Crossing a tax band never leaves you worse off. Here is what a rise is actually worth at each level, and the one band where the arithmetic turns sharp.
Forms
What is a P45?The form that carries your pay and tax from one job to the next. What each part is for, what to do when it does not arrive, and why it matters more than it looks.What is a P60?The certificate that closes a tax year: what it must show, when it has to reach you, what to check it against, and why it is the document to keep.What is a P11D?The form that reports a company car, medical cover or an interest-free loan to HMRC, and the route by which those things end up costing you tax through your payslip.
Reliefs
Working from home tax reliefThe deduction for household costs ended on 5 April 2026. What that means for this tax year, which earlier claims are still open, and the narrow test those claims have to meet.Uniform tax rebateA small, repeating claim for washing your own work clothing. Who it applies to, what it is genuinely worth, and why it is not worth paying anyone to make it for you.
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Rates and thresholds
Income tax bandsEach band, and why only the slice above a threshold is taxed at the higher rateNational Insurance ratesThe rates, the thresholds, and why a bonus month costs more than a twelfth of a yearPersonal AllowanceWhat it is worth, how it reaches your payslip, and where it tapers awayStudent loan thresholdsEvery plan’s threshold, and what payroll takes from each paydayPlan 2 threshold freezeThe Plan 2 threshold, the announced freeze, and what it costs a graduateMinimum wage ratesEvery age band and the apprentice rate, and what each one leaves after taxStatutory pay ratesMaternity, paternity, shared parental and sick pay, and how long each one runsTax year datesWhen the year starts and ends, and how payroll numbers the weeks and monthsThe threshold freezeWhat is frozen, until when, and what crossing a frozen line actually doesEmployer National InsuranceWhat an employee costs an employer on top of the salary itself