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HMRC internal manual

Employment Income Manual

Travel expenses: general: choice of route

Sections 337 to 339 ITEPA 2003It is not necessary for the employee to make a business journey by the shortest route in order to obtain a deduction under Sections 336 to 339 ITEPA 2003. Another route may be more appropriate. For example, it may be appropriate to go round London on the M25 rather than driving through the middle. It is also acceptable to make a short detour for a meal.

There are limits to this flexibility and you should take care to ensure that it is not abused. A significant detour to visit a particular restaurant is not acceptable. That part of the journey should be treated as private and no deduction permitted. An employee travelling on business who makes a detour for private purposes will be entitled to a deduction for the cost of the business part of the journey but not for the private detour.