Discrepancies between pension calculations in BrightPay and other pension providers like Smart Pension may occur due to tax relief at source. 

This relief impacts calculations, with amounts being adjusted for a 20% tax relief by the pension provider. 

To resolve such discrepancies, review the tax relief settings in BrightPay by selecting the employee, clicking on the spanner icon next to their pension amount, and adjusting the tax relief basis if necessary.

Ensure that the correct tax relief method expected by the provider, such as 'tax relief at source,' is applied.