Accounts Receivable

12 Months Ended

Jul. 31, 2021

Receivables [Abstract]

Accounts Receivable

Accounts Receivable

Accounts receivable consist of the following at July 31, 2021 and 2020:

	2021		2020
Receivables from commercial and international customers	$	86,890,000	67,109,000
Unbilled receivables from commercial and international customers	36,131,000		21,588,000
Receivables from the U.S. government and its agencies	33,381,000		32,870,000
Unbilled receivables from the U.S. government and its agencies	3,356,000		7,018,000
Total accounts receivable	159,758,000		128,585,000
Less allowance for doubtful accounts	1,648,000		1,769,000
Accounts receivable, net	$	158,110,000	126,816,000

Unbilled receivables as of July 31, 2021 relate to contracts-in-progress for which revenue has been recognized, but for which we have not yet earned the right to bill the customer for work performed to-date. Under ASC 606, unbilled receivables constitute contract assets. Management estimates that a substantial portion of the amounts not yet billed at July 31, 2021 will be billed and collected within one year.

As of July 31, 2021, 23.0%, 12.7% and 12.1% of total accounts receivable related to U.S. government and its agencies, AT&T, Inc. and Verizon Communications Inc., respectively. Except for the U.S. government and its agencies, which represented 31.0%, respectively, no other customers accounted for greater than 10.0% of total accounts receivable as of July 31, 2020.