The duty on employers to automatically enrol workers and employees working in the UK into qualifying workplace pensions was introduced in October 2012. New rules have been introduced which mean that start-up businesses first paying PAYE from 1 October are under a legal duty to put staff straight into a workplace pension as soon as they employ them. Other auto-enrolment changes are in the pipeline too. This will be relevant for foreign companies setting up a business or branch in the UK.
Further information about this can be found here:
https://www.clydeco.com/blog/the-hive/article/workplace-pensions-and-new-start-ups