Some people are in a different world!
Try 17p a mile
Well, you must be getting a company car or allowance then, as that’s the IR rate for someone with those. 45p is the IR rate for those who provide and fund their own vehicle.
FWIW, I’m a ‘mobile’ consultant working for a global IT consultancy, so same as the OP I’m expected to work on client sites. We pay 17p a mile for those on a car allowance or with a co-car with a diesel engine larger than 2 litres. Hotels range from 75 to 175 depending on where in the country, and up to 30 a night for evening meal. Public transport is reimbursed at cost but can only claim for standard class travel. The only thing I have to do, is deduct the cost of travel from my home to my ‘base office’ which is 8 miles away. So 3 quid gets knocked off every fuel claim.
If I was the OP I wouldn’t touch this company with a barge-pole, I’ve got a pretty good idea who it is.