Toolkit

Starting a New Job: A Practical Checklist

Everything you need to do before and after your first day — from sorting your tax code to understanding your payslip and probation period.

Created by 21YH Team Last Updated April 2026
Employment & Work

What this toolkit covers

  • Documents to bring on your first day
  • How to check your tax code is correct
  • Understanding your payslip and deductions
  • What probation means and what to expect
  • Your rights from day one

Before you start

Make sure your employer has your National Insurance number and bank details. Dig out your passport or right-to-work documents — your employer is legally required to check these before your start date.

Your tax code

Your payslip will show a tax code — something like 1257L. This tells your employer how much of your income is tax-free. If it looks wrong, contact HMRC to check. An incorrect tax code can mean you overpay or underpay tax.

Probation periods

Most jobs include a probation period of 3–6 months. During this time your employer may have a shorter notice period. Use this time to show what you can do and ask questions freely.