For tax purposes there are two types of contract. Firstly, where the business owns or will own the car by the end of the contract or where your business rents/leases the car without ever owning it.
A tax deduction for 85% of the rental payments can be claimed. If the car has CO2 emissions of 130g/km CO2 or less, you can claim the full cost of the charges. The tax relief for leasing or buying is much the same in the long run. Consider your cash flow circumstances and choose the deal that best suits you.