6.	Unbilled Accounts Receivable and Significant Concentrations

Unbilled accounts receivable represent revenues earned in connection with products and/or services delivered for which we are unable to issue a formal billing to the customer at the balance sheet due to either timing of invoice processing or delays due to fixed contractual billing schedules. A significant portion of our unbilled accounts receivable consist of carrier services and cybersecurity hardware and software products delivered but not invoiced at the end of the reporting period. Unbilled receivables consist of the following by customer type as of the periods presented below:

	DECEMBER 31,
	2017		2016

Government	$	7,872,675	$	7,833,828
Commercial		258,773		278,862

Unbilled accounts receivable	$	8,131,448	$	8,112,690

Significant Concentrations

Customers representing ten percent or more of consolidated unbilled accounts receivable are set forth in the table below as of the periods presented:

	DECEMBER 31,
	2017	2016
	As a % of	As a % of
Customer Name	Receivables	Receivables

U.S. Department of Homeland Security HQ	11%	18%
U.S. Immigration and Customs Enforcement	27%	13%
U.S. Transportation Safety Administration	12%	—