Travel expenses: general: scale of expenditure: subsistence
Section 338 ITEPA 2003
An employee on secondment at a temporary workplace may obtain relief for accommodation costs (see EIM31836) and also for the costs of subsistence attributable to staying at the temporary workplace. This covers necessary food and drink and may also cover costs associated with accommodation, such as utility bills and personal expenditure attributable solely to the business travel. Relief may also be due for the cost of travel between the temporary accommodation and the temporary workplace (see example 4 in EIM31838).
Payments for expenses incidental to the business travel may also be made tax-free by the employer up to the limits imposed by Section 241 ITEPA 2003, see EIM02710.
There are no HMRC authorised subsistence rates for general application, although there are limited agreements for particular industries (see for example EIM66140 for lorry drivers). Accurate rates across the whole range of different circumstances would be very complex and would be difficult to create and maintain. A simple list of agreed rates would run the risk of permitting excessive relief or being inadequate and so of little practical use. For that reason you should not permit the use of generalised published rates such as those of the US Internal Revenue Service, or those published by the UN.
A dispensation may be granted where an employer makes appropriate scale rate payments for subsistence, see EIM30057.