This Practice Note sets out the legal issues surrounding who is a former employer in the context of the employer debt/section 75 debt regime. In particular, this Practice Note considers the requirements of the Occupational Pension Scheme (Employer Debt) Regulations 2005, SI 2005/678, the impact of the cases Cemex UK Marine v MNOPF Trustees and PNPF Trust Co v Taylor, as well as the circumstances in which an employer ceases to be an employer for section 75 debt purposes (both in ongoing and frozen schemes).