EIM32230 - Travel expenses: travel for necessary attendance: passing work on the way to somewhere else
Sections 337 and 338 ITEPA 2003
An employee may pass a permanent workplace on the way to or from a temporary workplace. If the employee stops and performs substantive duties at the permanent workplace then there are two journeys; ordinary commuting between home and the permanent workplace and a business journey between the permanent workplace and the temporary workplace. A deduction will be due under Section 337 ITEPA 2003 for the cost of the second of these journeys, but there is no deduction for the first.
If the employee does not stop at the permanent workplace, or any stop is incidental to the journey to the temporary workplace, the whole of the journey is a single journey. A deduction will be due under Section 338 ITEPA 2003, because the single journey is to a temporary workplace, unless the journey is substantially ordinary commuting, see EIM32300. See also example EIM32231.