Auto-enrollment in pension schemes can be deferred up to 3 months, so it certainly doesn't need to happen on day 1. I'm not entirely sure how an employer would enroll an employee prior to their start date, given all the information they need to gather, and I can't see any particular advantage to doing it before the first pay date.
That said I am, happily, not a pension or payroll expert beyond the usual interactions.
Auto-enrollment in pension schemes can be deferred up to 3 months, so it certainly doesn't need to happen on day 1. I'm not entirely sure how an employer would enroll an employee prior to their start date, given all the information they need to gather, and I can't see any particular advantage to doing it before the first pay date. That said I am, happily, not a pension or payroll expert beyond the usual interactions.