For example using £7.50 per hour x 52 weeks/12 months to calculate a monthly wage is actually underpaying someone.
Instead, you should multiply by 52.1428 weeks as there are 52 weeks and 1 day in a year.
It may seem odd but it is technically correct – Debenhams were recently named and shamed for underpaying employees! Of course, if we complete your payroll, we will sense check this for you. Contact your Client Account Manager if you are concerned.