Note 12—Income Taxes

We estimate (i) income taxes in the jurisdictions in which we operate, (ii) net deferred tax assets and liabilities based on temporary differences that are expected to be recovered or settled at the enacted tax rates expected in future periods, (iii) valuation allowances for deferred tax assets and (iv) contingent tax liabilities for estimated exposures related to our current tax positions.

Pursuant to FASB guidance related to accounting for uncertainty in income taxes, we must recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained upon examination by the taxing authorities, based on the technical merits of the tax position and also the past administrative practices and precedents of the taxing authority. As of December 31, 2013 and 2012, we had not recognized any material amounts in connection with uncertainty in income taxes.

U.S. Federal and State Taxes

As an MLP, we are not subject to U.S. federal income taxes; rather the tax effect of our operations is passed through to our unitholders. Although we are subject to state income taxes in some states, the impact to the years ended December 31, 2013, 2012, and 2011 was immaterial.

Canadian Federal and Provincial Taxes

All of our Canadian operations are conducted within entities that are treated as corporations for Canadian tax purposes (flow through for U.S. tax purposes) and that are subject to Canadian federal and provincial taxes. Additionally, payments of interest and dividends from our Canadian entities to other Plains entities are subject to Canadian withholding tax that is treated as income tax expense.

Tax Components

Components of income tax expense are as follows (in millions):

	Year Ended December 31,
	2013			2012		2011
Current tax expense:
State income tax	$	1		$	2	$	2
Canadian federal and provincial income tax	99			51		36
Total current tax expense	$	100		$	53	$	38

Deferred tax (benefit)/expense:
State income tax	$	—		$	—	$	(2	)
Canadian federal and provincial income tax	(1		)	1		9
Total deferred tax (benefit)/expense	$	(1	)	$	1	$	7
Total income tax expense	$	99		$	54	$	45

The difference between tax expense based on the statutory federal income tax rate and our effective tax expense is summarized as follows (in millions):

	Year Ended December 31,
	2013			2012			2011
Income before tax	$	1,490		$	1,181		$	1,039
Partnership earnings not subject to current Canadian tax	(1,187		)	(1,046		)	(909		)
	$	303		$	135		$	130
Canadian federal and provincial corporate tax rate	25		%	25		%	27		%
Income tax at statutory rate	$	76		$	34		$	35

Canadian withholding taxes	$	19		$	18		$	12
Canadian permanent differences and rate changes	3			—			(2		)
State income tax	1			2			—
Total income tax expense	$	99		$	54		$	45

Deferred tax assets and liabilities are aggregated by the applicable tax paying entity and jurisdiction and presented net in “Other long-term liabilities and deferred credits” on our Consolidated Balance Sheet and result from the following (in millions):

	December 31,
	2013			2012
Deferred tax assets:
Book accruals in excess of current tax deductions	$	56		$	28
Total deferred tax assets	56			28

Deferred tax liabilities:
Property and equipment in excess of tax values	(398		)	(397		)
Total deferred tax liabilities	(398		)	(397		)
Net deferred tax liabilities	$	(342	)	$	(369	)

Generally, tax returns for our Canadian entities are open to audit from 2009 through 2013. Our U.S. and state tax years are generally open to examination from 2010 to 2013.