BIM82225 - Partnerships - computation and assessment: changes of partners
Where there is a complete change in the ownership of the partnership’s business that business is treated as having ceased and recommenced.
Where there is a partial change in ownership, so that at least one partner carries on the business both immediately before and immediately after the change, and the partnership carries on the same business both before and after the change, the business is treated as continuing.
The commencement and cessation rules however apply to individual partners joining or leaving the partnership - see BIM82260.
A more detailed consideration of the effects of changes in the composition of a partnership is at BIM82400 onwards.