This depends on what definition of pensionable earnings your employer uses – whether it’s qualifying earnings, basic earnings or total earnings.
Qualifying earnings: all your earnings between a lower and upper limit are included. For the 2022/23 tax year the lower limit is £6,240 and the upper limit £50,270 (and the government will review these limits every year). Qualifying earnings include bonuses, commission, overtime, sick pay and parental leave pay.
Basic earnings: all your earnings are included except bonuses, commission, overtime and similar payments.
Total earnings: all your earnings including bonuses, commission, overtime and similar payments, are included.