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HMRC internal manual

Partnership Manual

Introduction to Partnerships and Partnership Taxation: when does a partnership commence?

The date of commencement will be determined by the facts. If the partnership is formed through oral agreement, the partnership will commence when the terms of the oral agreement have been implemented, even where a written agreement to give formal expression to the oral agreement is subsequently executed. However, where a written agreement creates a partnership where none existed already, the agreement cannot have retrospective effect. Further guidance can be found at BIM82040.