How much do you give your nanny for petrol?

[Rebecca41]

My nanny is starting in December, and I'm just adjusting a sample contract I've got for her.

One section is about car costs, if she ever takes the DS's out in her car. (She's not living-in, so will use her own car for journeys). I don't know how much to reimburse her for petrol. I worked out what the petrol cost per mile would be for her car, and it comes to about 10p/mile, which can't be right. I was under the impression people usually get 20-40p/mile.

Any ideas? Thank you.

HMRC: Rates - Travel this tells you the maximum amount before it is considered to be profit. So you can pay up to 40p per mile for the first 10,000 miles a year.
If you don't pay 40p per mile, your nanny can claim tax relief on the difference between what you pay and 40p a mile - if that makes sense. See reference to P87 in Income Tax: Allowances and Reliefs, Employees