Document And Entity Information - shares	6 Months Ended
	Sep. 30, 2021	Nov. 19, 2021
Document And Entity Information
Document Type	10-Q
Document Period End Date	Sep. 30, 2021
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-31747
Entity Registrant Name	UNIVERSAL SECURITY INSTRUMENTS INC
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	52-0898545
Entity Address, Address Line One	11407 Cronhill Drive
Entity Address, Address Line Two	Suite A
Entity Address, City or Town	Owings Mills
Entity Address, Country	MD
Entity Address, Postal Zip Code	21117
City Area Code	410
Local Phone Number	363-3000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		2,312,887
Entity Central Index Key	0000102109
Current Fiscal Year End Date	--03-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Amendment Flag	false
Trading Symbol	UUU
Title of 12(b) Security	Common Stock
Security Exchange Name	NYSE