Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Schedule of Income before Income Tax, Domestic and Foreign

Income (loss) before provision for income taxes consisted of the following (in thousands):

	Year Ended December 31,
	2022	2021	2020
United Kingdom	(92,841)	(72,397)	(60,522)
Foreign	1,744	854	220
Loss before provision for income taxes	(91,097)	(71,543)	(60,302)

Schedule of Components of Income Tax Expense (Benefit)

The income tax provision for the years then ended comprised (in thousands):

	Year Ended December 31,
	2022		2021		2020
Current income tax provision
United Kingdom	$	—	$	—	$	—
Foreign	1,865		744		253
Total current expense:	$	1,865	$	744	$	253
Deferred income tax benefit:
United Kingdom	—		—		—
Foreign	(1,457)		(545)		(221)
Total deferred income tax benefit:	$	(1,457)	$	(545)	$	(221)
Total provision for income taxes	$	408	$	199	$	32

Schedule of Effective Income Tax Rate Reconciliation

A reconciliation of income tax expense computed at the statutory UK income tax rate to income taxes as reflected in the consolidated financial statements is as follows (in thousands):

	Year Ended December 31,
	2022		2021		2020
Income taxes at UK statutory rate	$	(17,309)	$	(13,592)	$	(11,458)
Permanent differences	14		69		340
UK R&D tax credit	5,423		3,747		1,664
Change in valuation allowance	15,038		29,180		8,683
State income taxes	10		1		(5)
Deferred tax asset true-up	8		80		919
Return to Provision	1,580		(854)		—
Equity Compensation	(782)		(8,302)		—
Change in UK Tax Rate	(3,609)		(10,147)		—
Other	35		17		(111)
	$	408	$	199	$	32

Schedule of Deferred Tax Assets and Liabilities

Significant components of the Company’s deferred tax assets and liabilities as of December 31, 2022, 2021 and 2020 consist of the following (in thousands):

	Year Ended December 31,
	2022		2021		2020
Net operating loss carryforward	$	44,227	$	35,947	$	10,075
Reserves and accruals	695		169		62
Share-based compensation	9,332		6,232		3,128
Charitable contributions	33		—		—
Total deferred tax assets	54,287		42,348		13,265
Valuation allowance	$	(51,909)	$	(41,483)	$	(13,000)
Depreciation	(154)		(99)		(44)
Total deferred tax liabilities	(154)		(99)		(44)
Net deferred tax assets	$	2,224	$	766	$	221

Summary of Valuation Allowance

Changes in the valuation allowance for deferred tax assets during the years ended December 31, 2022, 2021 and 2020 related primarily to the increases in net operating loss and were as follows (in thousands):

	Year Ended December 31,
	2022		2021		2020
Valuation allowance at beginning of year	$	41,483	$	13,000	$	3,665
Increases recorded to income tax provision	15,038		29,180		8,683
Increases recorded to CTA	—		—		652
Decreases recorded to CTA	(4,612)		(697)		—
Valuation allowance at end of year	$	51,909	$	41,483	$	13,000