17. Inventory

At each reporting period the Group recognizes any necessary adjustments to reflect vehicle inventory at the lower of cost or net realizable value. Further detail on the estimates made in the calculation of net realizable value is set out in Note 4.2.

As at December 31 the inventory provision is stated as follows:

During the year £1,175.1 million (2021: £447.2 million, 2020: £161.2 million) was recognized as an expense for inventory carried at net realizable value. This is recognized in cost of sales.

The sensitivity of the inventory provision, based upon a 2% change in the expected selling price of inventory input, is as follows:

As at December 31, 2022 inventory of £170.7 million (2021: £273.3 million) was held as security against stocking loans.