Your final pay arrives on the next normal payday after your last working day. Salary up to the leaving date, unused holiday pay, any PILON, and any redundancy figure are usually paid together in that final packet. Most UK employers pay monthly on a fixed day, so the wait can be up to a month depending on when in the cycle you leave.
There's no UK law requiring final pay within a specific number of days. The default is your normal payroll cycle. So if you're paid monthly on the 25th and your last working day is the 10th, you'll get your final pay on the 25th. If your last day is the 26th, you'll get most of your normal salary on the 25th and the few remaining days plus any extras on the following 25th.
What's typically in the final pay packet: salary up to and including your last working day (pro-rated for partial months), unused statutory and contractual holiday paid out as cash, any PILON if you were paid in lieu of notice rather than working it, any redundancy figure if applicable, any contractual bonus or commission you've earned but not been paid yet. Each of these has its own tax treatment.
Tax treatment varies. Salary, holiday pay, PILON, and earned bonuses are all taxable as normal earnings under PAYE and subject to National Insurance. Statutory redundancy pay is tax-free up to £30,000 (the cap covers most non-executive redundancies). Genuine ex-gratia termination payments above and beyond statutory minimums can also fall within the £30,000 tax-free allowance, though PILON specifically does not since the 2018 reforms.
If your final pay arrives and a figure looks wrong, the first step is asking payroll for a breakdown. Salary calculations, holiday accrual, and PILON arithmetic are all things that get mistakes from time to time. A polite query usually fixes anything that's straightforwardly wrong. Keep the email trail because resolution sometimes takes a couple of payroll cycles.
If the employer fails to pay or pays significantly less than the contract requires, that's an 'unlawful deduction from wages' under the Employment Rights Act 1996. You can raise a grievance, then escalate to ACAS early conciliation, then potentially a tribunal claim. Time limits are short (three months less one day from the date of the deduction), so don't delay if a serious dispute develops.
P45 paperwork should arrive shortly after your final pay. Some employers send it the same day; some take a couple of weeks. You'll need the P45 to give to your new employer so they can put you on the right tax code and avoid emergency-tax overpayments. If you don't receive it within a month, chase HR.
If you've moved to self-employment or freelance work rather than a new employer, you'll need to register with HMRC and start filing self-assessment. Your final pay will be in the tax year ending in April; anything earned after that goes on the next year's return. Keep your P45 because it sets your starting position for the year.
Practical recommendation: confirm your final pay date with HR before you leave, ask for a written breakdown of what to expect in the final packet (salary, holiday, PILON, deductions), and check the figures land correctly when payday arrives. If anything's wrong, raise it that day; payroll teams have the easiest time fixing things while the leaver event is fresh in the system.
General information about UK employment law. For your specific situation, contact ACAS or an employment-law solicitor.