It’s for each employer to decide which basis of earnings to use when working out employee contributions. This decision is likely to be based on your workforce profile, pay structure and whether or not you’d like to provide benefits above the statutory minimum for your employees.
We’re not allowed to recommend an earnings basis to you. But speaking to a payroll professional or financial adviser could help you decide.
For more information on choosing an earnings basis, see www.thepensionsregulator.gov.uk/docs/detailed-guidance-4.pdf.