Understanding Your Payslip: Tax Codes, National Insurance and Pension Contributions Explained

Every month (or week), a slip of paper or PDF lands in your inbox showing your pay — and a list of deductions that can look like a foreign language. Tax codes, National Insurance, pension contributions: most of us just check the number at the bottom and move on.

But understanding your payslip matters. It's how you catch mistakes (an incorrect tax code could cost you hundreds of pounds), understand exactly what you're saving for retirement, and get a true picture of your take-home pay. This guide breaks down the main sections of a UK payslip in plain English, using the rates for the 2026/27 tax year (6 April 2026 to 5 April 2027).

What has to be on your payslip

By law, your employer must give you a payslip showing at least:

• Your gross pay (before deductions)
• The amount of each deduction, and what it's for
• Your net pay (what actually lands in your bank account)
• If your pay varies by hours worked, the number of hours you're being paid for

Let's go through the main deductions one by one.

1. Income tax and your tax code

Income tax is the biggest deduction for most employees. How much you pay depends on your tax code, which tells your employer how much of your income is tax-free before the rest gets taxed.

The standard tax code

For most employees with one job and no unusual circumstances, the 2026/27 emergency and standard tax code is 1257L. The basic Personal Allowance for 2026/27 is £12,570 across the whole of the UK (HMRC, 2026).

Here's how to read it:

• 1257 relates to your tax-free Personal Allowance of £12,570 — the number is simply the allowance with the last digit dropped.
• L means you're entitled to the standard tax-free Personal Allowance.

Other common letters you might see:

• BR — all your income from this job is taxed at the basic rate (often used for a second job)
• K — you have income that isn't being taxed elsewhere (e.g. company benefits) that outweighs your allowance
• M or N — you're receiving or have transferred part of the Marriage Allowance
• S — you're taxed under Scottish rates; C — Welsh rates

Why your tax code matters

If your tax code is wrong, you could be paying too much or too little tax. This can happen when you start a new job, have more than one income source, receive company benefits (like a car), or your circumstances change (marriage, additional income). It's worth checking your tax code against your latest HMRC coding notice, and contacting HMRC directly if something looks off.

How much tax you actually pay

For 2026/27, income tax is charged at 20% (basic rate), 40% (higher rate) and 45% (additional rate), with no tax due on income up to the £12,570 Personal Allowance (House of Commons Library, 2026). The basic rate applies to income up to £37,700 above your Personal Allowance, the higher rate from there up to £125,140, and the additional rate above that.

For example, on a £56,000 salary: the first £12,570 is tax-free, the next £37,700 is taxed at 20% (£7,540), and the remaining £5,730 is taxed at 40% (£2,292) (inniAccounts, 2026).

One thing worth knowing: if you earn over £100,000, your Personal Allowance starts shrinking — it's reduced by £1 for every £2 of income above £100,000, and disappears entirely once income reaches £125,140 (Mercans, 2026). This creates an effective tax rate of 60% on income in that band — something a financial planner can often help mitigate through pension contributions.

2. National Insurance (NI)

National Insurance is a separate deduction from income tax, and it funds things like the State Pension and certain benefits.

For 2026/27, Class 1 employee National Insurance is charged at 8% on earnings between £12,570 and £50,270, then 2% on earnings above that (House of Commons Library, 2026).This rate has come down over recent years — the main employee NI rate was reduced from 12% to 10% at the 2023 Autumn Statement, and from 10% to 8% at the 2024 Spring Budget (House of Commons Library, 2026).

Unlike income tax, National Insurance doesn't have a simple "personal allowance" concept in the same way, but the thresholds are similar — you won't pay NI on the first slice of your earnings.

Why it matters beyond your payslip: the number of "qualifying years" of National Insurance contributions you build up over your working life directly affects how much State Pension you'll receive. If you have gaps (for example from time out of work, or living abroad), it's worth checking your National Insurance record on GOV.UK, as in some cases you can pay to fill gaps and boost your future State Pension.

3. Workplace pension contributions

If you're aged 22 or over, earn more than £10,000 a year, and work in the UK, your employer is legally required to automatically enrol you into a workplace pension — and to contribute towards it. This is called auto-enrolment.

How much goes in

For 2026/27, the total minimum contribution is 8% of qualifying earnings, made up of at least 3% from your employer, with the employee typically contributing the remaining 5% (which usually includes tax relief) (LITRG, 2026).

Contributions aren't usually calculated on your entire salary — they apply to a band of earnings known as "qualifying earnings," which for 2026/27 runs from £6,240 to £50,270 (MoneyHelper, 2026). So if you earn £30,000, your contributions are based on the portion of your salary between those two figures, not the full £30,000.

Tax relief — the "free money" bit

One of the most valuable (and most overlooked) features of pension saving is tax relief. When you put money into your pension, the government effectively refunds the tax you would have paid on it. Salary sacrifice arrangements can be even more tax-efficient — if your employer offers this, you also save on employee National Insurance contributions on top of the income tax relief (Wealthvieu, 2026).

Many employers also match extra contributions above the legal minimum. For example, if an employee increases their contribution from 5% to 8% and their employer matches by increasing to 6%, the total contribution rises to 14% of qualifying earnings instead of 8% — effectively an immediate 100% return on the extra amount put in, before any investment growth (Wealthvieu, 2026). It's always worth asking your HR or payroll team whether your employer offers matching, and up to what level.

Should you ever opt out?

You can choose to opt out of your workplace pension, but think carefully before doing so. Opting out means giving up your employer's contribution entirely — money that's essentially part of your remuneration package. Unless you have a specific and well-considered reason, most people are better off staying enrolled, even if it means a slightly smaller amount in take-home pay each month.

4. Other deductions you might see

Depending on your circumstances, your payslip may also show:

• Student loan repayments — deducted automatically once your income crosses the relevant repayment threshold for your loan plan
• Court orders or attachment of earnings — deductions required by law, such as for certain debts
• Benefits in kind adjustments — if you have a company car or private medical insurance, this can affect your tax code rather than appearing as a separate deduction
• Union subscriptions or salary sacrifice schemes — such as cycle-to-work schemes or additional pension contributions

A quick payslip checklist

Next time your payslip arrives, it's worth taking two minutes to check:

• Is your tax code correct for your circumstances? (Compare it to your latest HMRC coding notice)
• Is your National Insurance being deducted at the right rate for your earnings level?
• What percentage is going into your pension — and is your employer contributing the maximum they're willing to match?
• Does your gross pay match your contract or agreed salary?

Small errors can add up significantly over a working life — particularly with pension contributions, where even a 1–2% difference compounds substantially over the years.

Getting help

Payslips can throw up genuinely confusing situations — multiple jobs, benefits in kind, salary sacrifice, or a mid-year change in tax code. If something doesn't look right, HMRC and MoneyHelper are free, impartial places to start. For a fuller picture of how your pay, pension and tax position fit into your broader financial plan, speaking to a financial adviser can help you make sure you're not leaving valuable tax relief or employer contributions on the table.

This article is for general information only and does not constitute financial or tax advice. Tax rules can change, and how they apply depends on your personal circumstances. For advice tailored to your situation, please speak to one of our advisers.