The cost of hotel, subsistence, travelling and any other ancillary expenses reasonably incurred by the individuals whom UH engages in connection with the Services, the cost of any materials and the cost of services reasonably and properly provided by third parties and required by UH for the supply of the Services. Such expenses, materials and third party services shall be invoiced by UH at cost (other than expenses for travel by car which shall be invoiced at 40p per mile) and shall be accompanied by receipts or other evidence verifying such expenditure.