NHS Back Pay Calculator
When a pay award is agreed late, it's backdated — and the arrears land in one payslip. Enter your old and new salary to see how much back pay you're owed, and roughly what you'll keep.
How NHS back pay works
NHS pay awards take effect from 1 April, but they're often agreed months later. Your employer then pays the difference between your old and new salary for every month since April in a single lump — the back pay. The arrears are pensionable and taxable like normal pay, and student-loan repayments apply too if you have a loan. If you've changed bands, hours or employers since April, your arrears are worked out period by period — your payroll team can provide the breakdown.
Back pay questions
When is NHS back pay paid?
Usually within one to two pay runs of the award being implemented by your trust — often in the autumn for awards effective from April. Your trust's payroll or ESR notice will confirm the exact month.
Is back pay taxed?
Yes. It's taxed as income in the month it's paid, along with National Insurance, pension contributions and student loan where applicable. A big lump can temporarily use a higher tax band; HMRC's annual reconciliation normally evens this out.
Do I get back pay if I left the NHS?
Generally yes, for the period you were employed after the award's effective date — but you may need to contact your former employer's payroll, as leavers are sometimes paid separately or on request.
Does back pay include unsocial hours and overtime?
Awards uplift your basic pay, and enhancements calculated from basic pay (like unsocial hours percentages) are normally re-worked for the backdated period too. Flat-rate allowances may not be uplifted — check the award circular for your staff group.