Current tax — UK corporation tax4,4061,629
— overseas tax at prevailing local rates7,8467,755
— adjustment in respect of prior years(942)(218)
Total current tax expense11,3109,166
Deferred tax — origination and reversal of temporary differences(9,475)(7,116)
— adjustment in respect of tax rates(34)(62)
— adjustment in respect of prior years65148
Total deferred tax expense(8,858)(7,130)
Total income tax expense in the Consolidated Income Statement2,4522,036

The tax on the Group's profit before taxation differs from the standard rate of UK corporation tax of 19.75% (2016: 20.0%). The current tax rate used for the period is 19.75% based on rates already enacted in previous periods. The differences to this rate are explained below:

Profit before taxation28,56214,548
Tax at 19.75% (2016: 20.0%)5,6412,910
Effect of:
— expenses not deductible162235
— acquisition expenses565167
— one-off costs (foreign exchange/acquisition costs) in relation to the acquisition of Putney Inc.1,314
— research and development related tax credits(57)(231)
— patent box tax credits(2,086)(1,118)
— impact of financing (income not taxable)(741)(405)
— share of results of associate31
— effects of overseas tax rates(745)(608)
— adjustment in respect of prior years(291)(170)
— difference between current and deferred tax rates74
— change in tax rates(34)(62)
Total income tax expense in the Consolidated Income Statement2,4522,036

Recurring items in the tax reconciliation include: research and development related tax credits and patent box incentives; expenses not deductible; share of results of associate; and the impact of financing. The effective tax rate is 8.6% (excluding non-underlying items the effective tax rate is 21.9%).

Tax Credit/(Charge) Recognised Directly in Equity

Corporation tax on foreign currency translation1,234
Deferred tax on employee benefit obligations(535)385
Tax recognised in Consolidated Statement of Comprehensive Income(535)1,619
Corporation tax on equity settled transactions7581,366
Deferred tax on equity settled transactions78112
Total tax recognised in Equity8361,478

The Government has announced in the Finance Act 2016 that it intends to reduce the rate of corporation tax to 17% with effective from 1 April 2020, this was substantively enacted in September 2016. The Finance Act 2015 (No. 2) which was substantively enacted in October 2015 included provisions to reduce the rate of corporation tax to 19% with effect from April 2017. Deferred tax has been calculated using these rates based on the timing of when each individual deferred tax balance is expected to reverse in the future. To the extent that more deferred tax reverses after 1 April 2020 than expected then the impact will be a greater reduction on the net deferred tax liability.

The Group's future tax charge, and its effective tax rate could be affected by several factors including the impact of the implementation of the OECD's Base Erosion and Profit Shifting ('BEPS') actions.