The following are the major deferred tax liabilities and (assets) recognised by the Group and movements thereon during the current and prior reporting periods:

Accelerated
tax
depreciation
£m
Tax
losses
£m
Retirement
benefit
obligations
£m
Other
£m
Total
£m
At 1 January 201649.3(3.1)(5.3)(10.2)30.7
(Credit)/charge to income1.11.2(3.3)(1.0)
Credit to equity(1.4)(1.4)
Acquisition of businesses1.71.12.8
Transfers(0.5)(0.1)0.30.3
Exchange differences8.8(0.1)(0.7)(2.0)6.0
Effect of change in tax rate:
Income statement(1.6)0.10.20.1(1.2)
Equity0.40.4
At 1 January 201758.8(3.2)(5.3)(14.0)36.3
Charge/(credit) to income1.61.3(0.1)2.04.8
Credit to equity1.1(0.5)0.6
Acquisition of businesses(0.4)(0.3)(0.7)
Transfers(0.2)0.10.1
Exchange differences(1.8)(0.2)0.7(1.3)
Effect of change in tax rate:
Income statement1(11.2)(0.1)4.4(6.9)
Equity(0.1)(0.1)
At 31 December 201746.8(2.0)(4.5)(7.6)32.7

1 Net impact of:

  1. £6.8m net one-off tax gain resulting from a revaluation of the Group's US deferred tax liabilities. This is in relation to the passing of the Tax Cuts and Jobs Act in the US in December 2017 that reduced the US Federal corporate income tax rate.
  2. £0.1m in relation to other tax rate change impacts.

The following is the analysis of the deferred tax balances for financial reporting purposes:

2017
£m
2016
£m
Deferred tax liabilities57.268.8
Deferred tax assets(24.5)(32.5)
32.736.3

Other deferred tax assets relate to provisions recognised in the financial statements that are not yet deductible for tax purposes, in particular in relation to restructuring charges, share-based payments and local profit differences that are expected to reverse over time.

At the balance sheet date, the Group has unused tax losses of £35.6m (2016: £46.3m) available for offset against future profits. A deferred tax asset has been recognised in respect of £7.3m (2016: £14.0m) of such losses, based on management forecasts of future taxable profits against which the assets can be recovered in the relevant jurisdictions. No deferred tax asset has been recognised in respect of the remaining £28.3m (2016: £32.3m) of such losses where there remains uncertainty over the timing of utilisation relating to future profitability. The majority of losses may be carried forward indefinitely.

A deferred tax liability of £0.5m (2016: £nil) relating to the temporary differences on unremitted earnings of overseas subsidiaries has been recognised as the Group believes it is probable that these temporary differences will reverse in the foreseeable future. Temporary differences arising in connection with interests in associates and joint ventures are insignificant.