Auto-enrolment means that all employers have to enrol eligible employees into a workplace pension automatically. It’s short for “automatic enrolment for workplace pensions”.
In simpler terms, as long as you’re working as an employee and you’re over 22 years old, your employer has to provide you with a pension scheme.
The only exception is for directors who don’t have contracts of employment. Your own limited company cannot auto-enrol you without a specific contract of employment.