You’ll have auto enrolment duties as soon as you employ someone. This is known as your ‘duties start date’.
Some of your employees may not be eligible for auto enrolment, but you need to assess them as part of your auto enrolment duties from the day they start working for you. You’ll also need to send them an assessment notice telling them what their rights and options are.
The Pensions Regulator has a handy online checklist to help you work out what your duties are.