My accountant wont even let me claim on a sandwich if working away from home.
You can't claim on a sandwich if you're working at home!
For tax purposes, if an item has a dual purpose (ie private and business) then you technically you can't claim on it; so the tax office reckons.
I recently read about a food writer who ate in posh restaraunts and then did a write up about the food and service which was then published; it was his job (nice job) and the tax man refused to allow the cost of the meal as an expense since you require food to live.
But that aside, you can't claim for a sandwich when you're working; at home or anywhere else.
Tosh. You can claim for dual purpose items and my accountant puts them through with no problem (he does take his work seriously too). My dual purpose items are my van, landline, mobile, computer plus associated peripherals and consumables (ink, paper). Obviously I do apportion the percentages between work and personal but this is definitely allowed.