NIM06350 - Class 1 NICs: Expenses and allowances: Travelling expenses: Emergency call-out
Generally, where the cost of a journey would not in normal circumstances satisfy the conditions for exclusion from NICs under the travel rules, then it will not be capable of being excluded just because the journey was made in response to an emergency.
The only exception is where the employee has to perform duties at home and while travelling to an emergency at a permanent workplace. In these circumstances the cost of the travel may be excluded.