	Year Ended December 31,
	2019			2018			2017
Domestic	$	(47,218	)	$	(41,985	)	$	(16,642	)
Foreign		(4,607	)		(4,734	)		(2,945	)
Total	$	(51,825	)	$	(46,719	)	$	(19,587	)

For purposes of reconciling the Company’s provision for income taxes at the statutory rate and the Company’s provision (benefit) for income taxes at the effective tax rate, a notional 26% tax rate was applied as follows (in thousands):

	Year Ended December 31,
	2019			2018			2017
Income tax at federal statutory rate	$	(10,883	)	$	(9,811	)	$	(6,659	)
Increase (decrease) in tax resulting from:
State income tax expense, net of federal tax effect		(3,657	)		(2,749	)		(421	)
Nondeductible permanent items		3,522			(1,522	)		1,506
Foreign rate differential		(367	)		552			599
Tax rate change		—			134			7,226
Adjustment to deferred taxes		(1,904	)		307			37
Change in valuation allowance		22,481			15,805			(2,291	)
Uncertain tax positions		128			143			76
Nonqualified stock option and performance award windfall upon exercise		(9,128	)		(1,983	)		—
Other		233			(80	)		(26	)
Total	$	425		$	796		$	47

The difference between the statutory federal income tax rate and the Company’s effective tax rate in 2019, 2018 and 2017 is primarily attributable to the effect of state income taxes, difference between the U.S. and foreign tax rates, deferred tax state rate adjustment, share-based compensation, true up of deferred taxes, other non-deductible permanent items, and change in valuation allowance. In addition, the Company’s foreign subsidiaries are subject to varied applicable statutory income tax rates for the periods presented.

	Year Ended December 31,
	2019			2018			2017
Current:
Federal	$	—		$	—		$	(23	)
State		139			48			51
Foreign		116			753			31
		255			801			59
Deferred:
Federal		(16,460	)		(11,425	)		3,307
State		(5,100	)		(3,250	)		(669	)
Foreign		(751	)		(1,135	)		(359	)
		(22,311	)		(15,810	)		2,279
Change in valuation allowance		22,481			15,805			(2,291	)
Total	$	425		$	796		$	47

The net deferred tax assets (liabilities) are comprised of the following (in thousands):

	As of December 31,
	2019			2018
Deferred tax assets
Lease liability	$	4,295		$	278
AMT credit		9			11
Accrued expenses		2,837			2,057
Deferred revenue		—			549
Net operating loss carryforward		50,950			34,662
Other assets		6,967			2,343
Property and equipment		—			123
Intangible assets		2,416			836
Valuation allowance		(24,637	)		(25,079	)
Total net deferred tax assets		42,837			15,780
Deferred tax liabilities
Deferred commissions		(4,308	)		(3,215	)
Deferred revenue		(336	)		—
Intangible assets		(7,948	)		(7,295	)
Property and equipment		(296	)		—
Debt discount		(26,589	)		(4,986	)
Right-of-use asset		(3,909	)		—
Deferred state taxes		(1,101	)		(1,233	)
Other		(352	)		—
Total deferred tax liabilities		(44,839	)		(16,729	)
Total non-current deferred income tax liabilities	$	(2,002	)	$	(949	)

A valuation allowance is recorded to reduce deferred tax assets to the amount that is more likely than not to be realized based on an assessment of positive and negative evidence, including estimates of future taxable income necessary to realize future deductible amounts. A significant piece of objective negative evidence evaluated was the cumulative loss incurred over the three-year period ended December 31, 2019. Such objective evidence limits the ability to consider other subjective evidence such as its projections for future growth. On the basis of this evaluation, at December 31, 2019 and 2018, a valuation allowance of $24.6 million and $25.1 million, respectively, has been recorded.

As of December 31, 2019, the Company has accumulated federal and state net operating loss (“NOL”) carryforwards of $165.0 million and $134.3 million, respectively. Of the $165.0 million of federal NOL carryforwards, $57.9 million was generated before January 1, 2018 and is subject to the 20-year carryforward period (“pre-Tax Act losses”). The remaining $107.1 million (“post-Tax Act losses”) can be carried forward indefinitely but is subject to the 80% taxable income limitation. The pre-Tax Act U.S. federal and state net operating loss carryforwards will expire in varying amounts through 2037. The Company completed a Section 382 study for the period through March 31, 2019 and determined that a Section 382 ownership change occurred on December 31, 2017 subjecting all pre-Tax Act losses to a utilization limitation; however, such limitation is not expected to result in NOLs expiring unused. Any future annual limitation may result in the expiration of NOLs before utilization.

As of December 31, 2019 and 2018, the Company had combined foreign net operating loss carry-forwards available to reduce future taxable income of approximately $25.6 million and $25.5 million, respectively. As of December 31, 2019 and 2018, valuation allowances of $24.6 million and $25.1 million, respectively, had been recorded against the related deferred tax assets for those loss carry-forwards that are not more likely than not to be fully utilized in reducing future taxable income.

The following changes occurred in the amount of unrecognized tax benefits (in thousands):

	Year Ended December 31,
	2019		2018			2017
Beginning balance of unrecognized tax benefits	$	469	$	326		$	250
Additions for current year tax positions		106		142			65
Reductions for prior year tax positions		—		(14	)		—
Ending balance (excluding interest and penalties)		575		454			315
Interest and penalties		22		15			11
Total	$	597	$	469		$	326

For the year ended December 31, 2019, 2018 and 2017, the Company has recorded income tax expense of $128,000, $143,000 and $76,000, respectively, related to uncertain tax positions. The Company’s policy is to recognize potential interest and penalties related to unrecognized tax benefits associated with uncertain tax positions, if any, in the income tax provision. At December 31, 2019, 2018 and 2017, the Company had accrued $22,000, $15,000 and $11,000 in interest and penalties related to uncertain tax positions.

The Company is subject to taxation in the United States and various states along with other foreign countries. The Company has not been notified that it is under audit by the IRS or any state or foreign taxing authorities, however, due to the presence of NOL carryforwards, all of the income tax years remain open for examination in each of these jurisdictions. The Company does not believe that it is reasonably possible that the total amount of unrecognized tax benefits will significantly increase or decrease in the next 12 months.

Deferred income taxes have not been provided for undistributed earnings of the Company’s consolidated foreign subsidiaries because of the Company’s intent to reinvest such earnings indefinitely in active foreign operations. At December 31, 2019, the Company had $0.6 million in unremitted earnings that were permanently reinvested related to its consolidated foreign subsidiaries.