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HMRC internal manual

Business Income Manual

Meaning of trade: exceptions and alternatives: activities not connected with an existing trade

A trader’s operations that cannot be regarded either, as operations of his ordinary business or as ancillary to it, should be considered independently in the light of the principles indicated in BIM20050 onwards.

If they amount to the carrying on of a trade (or produce liability as miscellaneous income) and they have some connections with the operations of the trader’s ordinary business, they may in practice be merged with it.