Readers’ forum: Can train ticket be partly claimed for tax purposes?

My client a writer has raised a question about his weekly train fares to visit his elderly mother. Although this is a private trip he upgrades his rail ticket to first class because he is then guaranteed a table and he can work on the train. He works for the whole journey and a first-class carriage is also quieter. He has asked if the price difference between a standard return ticket and first-class ticket can be claimed as a travel expense on his accounts and tax return? My initial reaction was ‘no way’ because the trip is not ‘wholly and exclusively’ incurred for business purposes but now I’m not sure. Do readers have any thoughts? He is a higher rate taxpayer – his business is not incorporated – so there is quite a lot of tax and class 4 National Insurance involved.

As a separate question ...