Tax treatment of travel expenditure

My good friend Oliver is one of those friends who seems to always be either just back from or heading off to an exciting and exotic location. His Instagram makes me rather green with envy as I scroll and ‘like’ on my tea break looking out at the grey landscape wind and rain that awaits me on my commute home. He is employed as a junior garden designer for a company based in London with a large portfolio of clients owning multiple properties in far-flung locations with the most elaborate gardening projects on the go. The company is owned and managed by Penny who despite having a keen eye for form and colour gets in a muddle when it comes to organising payment of the expense claims and Oliver frequently DMs me with a query when he is unsure if the...