Self-employed business mileage

MoneySavingUser

is this correct?

there are 2 ways to claim:

1. Claim tax relief using the approved mileage rates i.e. 40 p for first 10000 miles

using this method you cannot claim capital allowances

2. claim for a proportion of the costs of running the car i.e. 20% business use

using this method you can also claim capital allowances

also what exactly is classed as business mileage?

i.e. employees cannot claim for travel to normal place of work

but if a self-employed person agrees to provide services to a company for 1 month can they claim for travel to there?

i.e. a computer systems teacher teaching a company's staff how to use their new computer system for 1 month?

Innerapple

If you're usual place of work while self employed is your home then any travel away from home should be claimable.
Did you factor travel expenditure into the amount you charged?
You also need to decide whether to claim a % of your car costs or mileage at .40p per mile for the first 10,000 miles. As you only mention one month of travel then mileage will probably be the simplest thing to work out rather than calculating what percentage of the total usage of the vehicle is for business and compiling total expenses on the vehicle.
Hope this points you in the right direction while you wait for an expert to properly answer!