EIM01530 | Employment income: meals: cash allowances to employees
From HM Revenue & Customs · Employment Income Manual
A cash allowance for meals taken at the normal workplace is taxable as “earnings” within section 62 ITEPA 2003 (see EIM00510 onwards, and Sanderson v Durbridge (36TC239)).
Where the cost of a meal is part of the expenses incurred in travelling, see EIM31815.