Night shift allowance
A night shift allowance is extra pay, agreed in the contract, for working when other people are asleep. UK law does not set the amount. It does not even require the extra. What it does require, for people who qualify as night workers, is a limit on hours and a health assessment.
The legal night, and the contractual extra
Night time is 11pm to 6am unless an agreement sets a different period of at least seven hours that includes midnight to 5am. A night worker regularly works at least three hours in that window. Their normal hours must not exceed an average of eight hours in 24. The employer should offer a free health assessment before night work starts and at regular intervals. Those duties sit on the GOV.UK night working page. A percentage on top of the hourly rate does not.
The National Minimum Wage has no night rate. The age rate from 1 April 2026 is the floor for the pay reference period, including nights. An allowance you choose to pay can count towards that floor. It cannot be used to drag a different hour below it. If the allowance is part of the normal week, it can also belong in holiday pay, including in basic pay where the premium is simply the rate for those shifts. The holiday pay page explains the 4 weeks and the 1.6 weeks. This page does not pick a number for the allowance, because there is no statutory one to pick.
What you record
Put the night on the rota with its real start and end. Shiftbrook will not multiply the hour by 1.25, or by any other factor, when the clock passes 11pm. There is no allowance field. The timesheet approves the hours. The CSV leaves with those hours and no rate attached. Payroll adds the contractual premium, or it does not.
A sleep-in, where the person is expected to sleep and is woken for tasks, is not the same as a night shift they work through. The minimum-wage treatment of sleep-ins is on the on-call entry. Do not pay a night allowance and assume the sleep-in question is finished. Young workers should not ordinarily work at night. A graveyard shift entry covers the overnight block as a planning name. This entry covers the money, which is the contract, and the protections, which are the statute.
Sources
Graveyard shift · On-call rota · Minimum wage · Holiday pay calculator