I have recently set up as a sole trader and I am a little unclear about where the line falls as to what _are_ and what _aren't_ legitimate business expenses. Two cases: 1. I have a mobile phone that I use both for business and personal use - can I claim the line rental as business expenses? 2. I travel both for business and pleasure - ie I might go to Spain to research a new business idea but also to have a holiday at the same time. Can I claim the whole cost of the trip as a business expense? What proof, if any, is needed that I was doing business 'things' on my trip? Any advice would be most appreciated - many thanks! Richard