What can an actor claim for clothes as a business expense?
The general rule for clothing costs as a deductible expenses is based on a case from 1983 ( Mallalieu v Drummond  and this is still the case that HMRC use today
The judges decision was that a self-employed person could not claim a deduction for the cost of ‘a wardrobe of everyday clothes’ even if they were used solely for work. There is an inevitable non-business purpose in the acquisition of such clothing: the provision of warmth and decency.
This decision does not mean that the cost of clothing is always disallowed, the costs of a ‘uniform’ or protective clothing. The cost of clothing acquired for a role in a film, stage or TV performance is also allowable. The clothing is not part of ‘an everyday wardrobe’; it is ‘costume’ used in a performance.
HMRC’s notes on clothing as an expense for the self employed can be found here