Every employer in the UK must put certain staff into a workplace pension and contribute to it. This is called automatic enrolment.

If you have employed staff for the first time, since 1st October 2017, your automatic enrolment duties will have begun on the day your first member of staff starts work. 

If you are starting a new business and taking on a member of staff then as well as setting up a PAYE scheme and deciding what to pay, you will need to assess them to see if you need to put them into a workplace pension scheme. This is a legal duty.

The Pensions Regulator has online information that will help you find out what tasks you need to complete and by when http://www.thepensionsregulator.gov.uk/en/employers