Income taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Deferred tax assets
Deferred revenue	$ 1,432	$ 1,224
Capital allowances for tax purposes	1,010	823
Accruals	4,936	5,037
Tax losses	2,000	1,456
Stock based compensation	554	540
Deferred foreign currency losses	338	407
Recurring commission liability	241	186
Lease liabilities	517	552
Other	39	166
Gross deferred tax assets	11,067	10,391
Set-off of deferred tax balances	(6,652)	(6,098)
Net deferred tax assets before valuation allowance	4,415	4,293
Less valuation allowance	(647)	(511)
Net deferred tax assets	3,768	3,782
Deferred tax liabilities
Capital allowances for tax purposes	3,629	3,494
Intangible assets	3,735	3,559
Prepaid expenses	232	133
Deferred foreign currency gains	5,673	6,186
Investment in subsidiaries	646	427
Deferred commissions	719	802
Lease assets	638	482
Other	352	202
Gross deferred tax liabilities	15,624	15,285
Set-off of deferred tax balances	(6,652)	(6,098)
Net deferred tax liabilities	8,972	9,187
Net deferred tax liability	(5,204)	(5,405)	$ (8,328)
The gross movement in net deferred tax assets/(liabilities) is as follows:
Opening balance	(5,405)	(8,328)
Foreign currency translation	(268)	(1,415)
Other comprehensive income	(50)	19
Statement of Income charge	519	4,319	(4,590)
Closing balance	$ (5,204)	$ (5,405)	$ (8,328)