Something I had when temping (contracting) as a cadmonkey. Gov decided you are entitled to food and travel expenses as you are not a salaried employee; use umbrella accountancy firm to deduct expenses for the week (food and fuel) from your wage, pay tax on subsequent figure, have expenses added back minus a smallish fee for the accountants. Result is about 200 quid extra a month.
All of this is un-receipted - food allowance was £6 per day and fuel was 40ppm up to 10k miles a year. (I think there was an allowance for public transport also, but I never looked into that at the time)
So, that's about 120 quid a month in food allowance, added to about 25 quid of fuel every week. I'd work out the mileage and food and submit the expenses every friday.
I thought it was some sort of scam when my agency offered it... turns out I'd been missing out on topping up my earnings for ages, all according to government rules for contracted/temporary workers. They define a temporary contract as one that does not exceed 24 months continuous duration.

I always wondered why some of the contracts managers and contracted engineers at my last fulltime job were always going on about expenses.
Iirc you could claim these expenses if you were self employed or in partnership as a contractor through an agency or direct with a firm. All you had to do was have both parties confirm the status of your employment to the accountancy people and away you go.
I still think it sounds like a fiddle, but that's just me.
