Allowance for Doubtful Accounts Receivable and Sales Returns

12 Months Ended

Dec. 31, 2021

Receivables [Abstract]

Allowance for Doubtful Accounts Receivable and Sales Returns

Note 6. Allowance for Doubtful Accounts Receivable and Sales Returns

Activity in the allowance for doubtful accounts receivable (in thousands):

	Years ended December 31,
	2021		2020
Balance, beginning of year	$	598	$	484
Addition (reduction) to allowance	(319)		117
Amounts written off	—		(30)
Effects of foreign currency translation	(13)		27
Balance, end of year	$	266	$	598

Activity in the allowance for sales returns (in thousands):

	Years ended December 31,
	2021		2020
Balance, beginning of year	$	31	$	32
Reduction to allowance	—		(1)
Balance, end of year	$	31	$	31
Total, Allowance for Doubtful Accounts Receivable and Sales Returns	$	297	$	629

One customer individually comprised more than 10% of trade accounts receivable at December 31, 2021, with the customer accounting for 23% of trade accounts receivable. Two customers individually comprised more than 10% of trade accounts receivable at December 31, 2020, with the customers accounting for 19% and 10% each.

Two customers accounted for 30%, or $17.6 million, of consolidated revenue during the year ended December 31, 2021, in the Mobile Services segment.

Two customer accounted for 25%, or $17.3 million, of consolidated revenue during the year ended December 31, 2020, in our Mobile Services segment.