is the UK's membership body for social enterprises?

No. The question conflates a qualification with an industry body. The Level 5 Diploma in Health and Social Care Management Online (RQF, 120 Credits) is a regulated academic award, not a membership organisation. The UK’s primary membership body for social enterprises is Social Enterprise UK. This OTHM qualification is regulated by Ofqual (qualification number 610/1537/4) and sits on the Regulated Qualifications Framework. It provides management competencies for health and social care leaders. It does not grant membership to any trade body. Learners gain a diploma that meets entry requirements for Level 6 top-up degrees. It is assessed via assignment, not exam. The course is delivered online over twelve months for GBP 950. It is designed for deputy managers and team leaders seeking formal recognition of their management skills within the UK framework.