Staffing & Recruitment Insights | ACS Staffing Solutions Blog

What Is a Tax Code? How to Check Your Payslip?

Written by Chris Wright | Nov 4, 2026, 9:00:02 AM

You accepted a job at an advertised salary, then your first payslip arrived and the number at the bottom looked smaller than expected. Don’t panic. This payslip explained guide shows where your money goes and what to do if something looks wrong.

Why Take-Home Pay Is Lower Than Advertised Pay

Advertised pay is your gross pay, the amount before anything is taken off. Your net pay is what lands in your bank account. The gap is made up of legal deductions. Your employer must give you a payslip showing both figures, plus a breakdown of each deduction.

Payslip Deductions Explained

Income Tax

You pay Income Tax on earnings above your Personal Allowance, currently £12,570 a year for most people. Your employer takes it automatically through PAYE, so you don’t need to send HMRC anything.

National Insurance

National Insurance contributions build your entitlement to benefits such as the State Pension. You pay them once your earnings pass a set threshold, and they appear as a separate line on your payslip.

Workplace Pension

Under automatic enrolment, eligible workers are put into a pension scheme. You pay in a percentage of your pay, your employer adds their share, and you usually get tax relief too. You can opt out, but you would lose your employer’s contribution.

Other Deductions

You may also see student loan repayments, union fees or salary-sacrifice schemes. Each one should be labelled clearly.

What Is a Tax Code?

Your tax code tells your employer how much tax-free pay you get. A common code is 1257L. Emergency codes, often marked W1, M1 or X, are common on a first payslip and can mean you pay too much tax until HMRC has your details.

What to Do If Your Payslip Looks Wrong

  1. Check your tax code against the one on your HMRC personal tax account.
  2. Compare your hours and pay rate with what you agreed.
  3. Ask your employer or payroll team to explain any line you don’t recognise.
  4. Contact HMRC if your tax code is wrong, as it can fix it and refund any overpaid tax.

Get Payslip Support From ACS Staffing Solutions

Understanding your pay shouldn’t be a guessing game. At ACS Staffing Solutions, our team supports candidates from the first placement to the first payslip and beyond, whether you’re temping or looking for a permanent role.

Got a question about your pay, or looking for your next opportunity? Get in touch with ACS today and let’s talk.