Entity to be registered: Partnerships: Composition of a partnership
A partnership may be composed of natural persons (individuals), legal persons (corporate bodies) or both. However, a partnership cannot be a partner in another partnership (except in Scotland - see Scottish Partnerships).
If two firms combine in partnership, they will form one partnership composed of all the partners of both of the firms. This does not mean that the two original partnerships cease to exist in their own right and it may well be that the two original partnerships and the third created by combining those partners will each need to be registered separately for VAT.