v3.26.1
Cover - shares
 12 Months Ended
Mar. 31, 2026
Jul. 31, 2026
Document Information [Line Items]    
Document Type 20-F  
Document Registration Statement false  
Document Annual Report true  
Document Transition Report false  
Document Financial Statement Error Correction [Flag] false  
Document Shell Company Report false  
Entity Interactive Data Current Yes  
Document Accounting Standard U.S. GAAP  
ICFR Auditor Attestation Flag false  
Amendment Flag false  
Document Period End Date Mar. 31, 2026  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus FY  
Entity Registrant Name RAYTECH HOLDING LIMITED  
Entity Central Index Key 0001948443  
Entity File Number 001-42100  
Entity Incorporation, State or Country Code D8  
Current Fiscal Year End Date --03-31  
Entity Well-known Seasoned Issuer No  
Entity Voluntary Filers No  
Entity Current Reporting Status Yes  
Entity Shell Company false  
Entity Filer Category Non-accelerated Filer  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Address, Address Line One Unit 609, 6/F, Nan Fung Commercial Centre  
Entity Address, Address Line Two No.19 Lam Lok Street  
Entity Address, City or Town Kowloon Bay  
Entity Address, Country HK  
Entity Address, Postal Zip Code 00000  
Title of 12(b) Security Ordinary Shares $0.0001 par value per share  
Trading Symbol RAY  
Security Exchange Name NASDAQ  
Entity Common Stock, Shares Outstanding   5,874,743
Business Contact    
Document Information [Line Items]    
Contact Personnel Name Mr. Ching Tim Hoi  
Contact Personnel Email Address ray@raytech.com.hk  
Entity Address, Address Line One Unit 609, 6/F, Nan Fung Commercial Centre  
Entity Address, Address Line Two No.19 Lam Lok Street  
Entity Address, City or Town Kowloon Bay  
Entity Address, Country HK  
Entity Address, Postal Zip Code 00000  
City Area Code +852  
Local Phone Number 2117 0236