An employee may pass a permanent workplace on the way to or from a temporary workplace. If the employee has to stop and perform duties at the permanent workplace then there are two journeys:
Only the cost of the business journey (the second journey
identified above) can be excluded from NICs as business travel.
If, alternatively, the employee does not stop at the
permanent workplace, or any stop is incidental to the business
journey (for instance, if they stop merely to collect papers needed
for a meeting at the temporary workplace) then the cost of the
whole journey can be excluded from NICs.
See EIM32230 (previously SE32230 for further information.