In what circumstances may it be necessary for the employer to predict earnings for the purposes of pensions auto-enrolment?

It may be necessary for the employer to predict earnings where an employee has a pay reference period of longer than six weeks, for example quarterly or longer. This is because there is a six-week window for enrolling an eligible jobholder from the auto-enrolment date. Therefore, by the time the actual pay for a pay reference period of longer than six weeks has been calculated, the six-week auto-enrolment window will have expired.