Concentrations and credit risk

12 Months Ended

Mar. 31, 2020

Accounting Policies [Abstract]

Concentrations and credit risk

16 Concentrations and credit risk

The Company operates principally in the PRC (including Hong Kong) and grants credit to its customers in this geographic region. Although the PRC is economically stable, it is always possible that unanticipated events in foreign countries could disrupt the Company’s operations.

Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash and trade receivables. The Company does not require collateral to support financial instruments that are subject to credit risk. 

At March 31, 2019 and 2020, the Company had credit risk exposure of uninsured cash and deposits with maturities of less than one year in banks of approximately $7,527,000 and $9,111,000, respectively.

A substantial portion, 31%, 37% and 27% of revenue, was generated from one customer for the years ended March 31, 2018, 2019 and 2020, respectively.

The net revenue representing at least 10% of total net revenue are as follows:

	Year Ended March 31,
	2018				2019				2020
	$ in thousands		%		$ in thousands		%		$ in thousands		%
Customer A		3,579		31		3,715		37		3,573		27
Customer C		1,599		14		1,225		12		1,239		9
Customer B		1,662		14		1,027		10		313		2
Customer D *		1,115		10		21		—		—		—
Customer E		1,050		9		996		10		—		—
		9,005		78		6,984		69		5,125		38

* That customer has stopped purchasing from us as of June 2017.

The following customers had balances of at least 10% of the total trade receivables at the respective balance sheet dates set forth below:

	March 31,
	2019				2020
	$ in thousands		%		$ in thousands		%
Customer C		136		23		241		30
Customer B		191		32		133		16
Customer A		127		21		99		12
Customer F		—		—		95		12
				76				70

At March 31, 2019 and 2020, these customers accounted for 76% and 70%, respectively, of net trade receivables. The trade receivables have repayment terms of not more than twelve months.