A provision is recognised if, as a result of a past event, the Group has a present legal or constructive obligation that can be estimated reliably, and it is probable that an outflow of economic benefits will be required to settle the obligation. Provisions are determined by discounting the expected future cash flows at a pre-tax rate that reflects current market assessments of the time value of money and the risks specific to the liability. The unwinding of the discount is recognised as a finance cost.

Details of the provisions recognised and the significant estimates and judgements can be seen in note 19.

Where the Group expects a provision to be reimbursed, the reimbursement is recognised as a separate asset when the reimbursement is certain.

A provision for vacant properties is recognised when the expected benefits to be derived by the Group from a contract are lower than the unavoidable cost of meeting its obligations under the contract. The provision is measured at the present value of the lower of the expected cost of terminating the contract and the expected net cost of continuing with the contract. Before a provision is established, the Group recognises any impairment loss on the assets associated with that contract. The main uncertainty is the quantum and/or timing of the amounts payable, and the time value of money has been incorporated into the provision amount to take account of this sensitivity.

Provision is also made for onerous contracts in loss-making stores and Autocentres which management do not expect to become profitable.

A rent review provision is recognised when there is expected to be additional obligations as a result of rent reviews where the review date has passed and the review has not yet concluded. This forms part of the Group's unavoidable cost of meeting its obligations under the lease contracts. The provision is based on management's best estimate of the rent payable after the review. Key uncertainties are the estimate of the rent payable after the review has occurred.

A dilapidations provision is recognised when there is future obligation relating to the maintenance of leasehold properties. The provision is based on management's best estimate of the obligation which forms part of the Group's unavoidable cost of meeting its obligations under the lease contracts. Key uncertainties are the estimates of amounts due.

Provisions for employer and product liability claims are recognised when an incident occurs or when a claim made against the Group is received that could lead to there being an outflow of benefits from the Group. The provision is based on management's best estimate of the settlement assisted by an external third party. The main uncertainty is the likelihood of success of the claimant and hence the pay-out; however, a provision is only recognised where there is considered to be reasonable grounds for the claim.