The guidance advises that "Where an ‘itinerant’ trader’s base of operations is at their residence, you should allow the costs of travelling between the residence and the sites at which the trader works. An itinerant trader is one who travels from their home to a number of different locations for the purely temporary purpose at each such place of their completing a job of work, at the conclusion of which they attend at a different location. A typical example would be a jobbing builder".
The guidance also advises that there are "qualitative limits" on the distance that an itinerant taxpayer could live from a location.
BIM37620 - Wholly and exclusively: duality of, or non-trade, purpose: travel costs: to and between sites