When you are considering a leasing contract it is important to remember that a contract is based on a fixed mileage and, should you exceed this mileage, you will be charged an excess mileage charge. This can work out quite costly so it's a good idea to take your time and work out as best as possible the mileage you will drive and ask for a personalised quote based on this. Many leasing companies will advertise low mileage contracts to attract customers as this makes the monthly rental lower, this can end up costing you a lot more.
Mileage on a leasing contract is usually advertised as the yearly mile i.e. 8000 or 8k per annum. If you take out a 3 year lease this would mean you will have a total contract mileage of 24,000 or 24k. One thing to remember is that although it's quoted as a yearly mileage any unused miles carry on to the remainder of the contract. If you take out an annual mileage of 8k on a 3 year contract and only use 6k you still have (24-6=18) 18,000 miles left to use in the following 2 years of your contract. Always ask if you are unsure if the mileage is per year or the total contract mileage.
The company you are leasing the vehicle from should always advise you of the excess mileage charge upfront and it should also be shown on your contract.
The excess mileage charge varies depending on the vehicle so please don't assume that because you have been quoted an excess mileage on one vehicle it will be the same across the board as it isn't.
See below example of a quote which shows contract mileage and excess mileage charges:
This example shows you that the annual mileage is 10000 and also shows you the total contract mileage is 30000. The excess mileage charge is 16.02p per mile.
If you were to drive 16000 miles in year one, 8000 miles in year 2 and 14000 in year 3 this would be a total mileage of 38000 , this is 8000 miles above the contract and the excess mileage charge would be 8000 x 16.02p= £1281.60.