Deferred tax assets and liabilities

Deferred tax assets and liabilities are as follows.

Deferred tax assets and liabilities relate mainly to property, plant and equipment and cash flow hedges taken through group equity.

Movements in deferred taxes during 2019 are as follows:

The major portion of the deferred tax on property, plant and equipment relates to the difference between the carrying amounts and tax bases in the valuation of the networks. The deferred tax liability relating to property, plant and equipment was caused mainly by the difference between the book values and tax bases in the valuation of the networks at the time of the introduction of corporate income tax for Stedin Group, accelerated depreciation for tax purposes applied in the past, the revaluation of the networks and the valuation of the acquired networks as part of the accounting for the acquisition of DNWG.

In December 2019, the Upper House of Dutch Parliament approved the bill to increase the corporate income tax rate to 25% in 2020, and then to 21.7% in 2021 and subsequent years. Calculations performed in 2018 still applied rates of 22.55% for 2020 and 20.5% as from 2021, which were the future statutory rates in 2018 but which were changed in 2019 to 25% and 21.7% respectively. This means that, depending on the expected time of realisation, the deferred tax assets and liabilities will be settled at different rates. The valuation of the deferred tax assets and liabilities as at 31 December 2019 is based on the rates applicable at the estimated times of realisation.

Movements in deferred taxes during 2018 are as follows:

Expiration periods for deductible temporary differences as at 31 December 2018 are as follows: