Income Taxes

9 Months Ended

Sep. 30, 2017

Income taxes



	For the three months ended September 30				For the nine months ended September 30
(in millions of Canadian dollars)	2017		2016		2017		2016
Current income tax expense	$	93	$	73	$	288	$	177
Deferred income tax expense	77		50		168		233
Income tax expense	$	170	$	123	$	456	$	410

During the three months ended September 30, 2017, legislation was enacted to increase the Illinois state income tax rate. As a result of this change, the Company recorded a deferred tax expense of $3 million in the third quarter of 2017 related to the revaluation of its deferred income tax balances as at January 1, 2017.

During the nine months ended September 30, 2017, the Company recorded a net deferred tax recovery of $14 million related to the revaluation of its deferred income tax balances as at January 1, 2017. This was due to legislation enacted in the second quarter to decrease the Saskatchewan provincial corporate income tax rate which resulted in a $17 million recovery, partially offset by the $3 million expense described above.

The effective tax rates for the three and nine months ended September 30, 2017, were 24.95% and 24.28%, respectively, compared to 26.23% and 25.26%, respectively, for the same periods in 2016.

The estimated 2017 annual effective tax rate for the three months ended September 30, 2017, excluding the discrete items of the foreign exchange gain of $105 million on the Company's U.S. dollar-denominated debt and the $3 million tax expense described above, is 26.50%.

The estimated 2016 annual effective tax rate for the three months ended September 30, 2016, excluding the discrete items of the foreign exchange loss of $46 million on the Company's U.S. dollar-denominated debt, and the settlement charge in respect of a corporate legal claim of $25 million, was 25.17%.

The estimated 2017 annual effective tax rate for the nine months ended September 30, 2017, excluding the discrete items of the management transition recovery of $51 million related to the retirement of the Company's Chief Executive Officer, the foreign exchange gain of $200 million on the Company's U.S. dollar-denominated debt, an insurance recovery of $10 million on a legal settlement, the $13 million charge associated with the hedge roll and de-designation and the $14 million net tax recovery due to tax rate changes described above, is 26.50%.

The estimated 2016 annual effective tax rate for the nine months ended September 30, 2016, excluding the discrete items of the foreign exchange gain of $153 million on the Company's U.S. dollar-denominated debt and the settlement charge in respect of a corporate legal claim of $25 million, was 26.50%.