v3.26.1
Cover
 12 Months Ended
Mar. 31, 2026
shares
Entity Addresses [Line Items]  
Document Type 20-F
Amendment Flag false
Document Registration Statement false
Document Annual Report true
Document Transition Report false
Document Shell Company Report false
Document Period End Date Mar. 31, 2026
Document Fiscal Period Focus FY
Document Fiscal Year Focus 2026
Current Fiscal Year End Date --03-31
Entity File Number 001-42739
Entity Registrant Name BLUEMOUNT HOLDINGS LIMITED
Entity Central Index Key 0002027815
Entity Incorporation, State or Country Code E9
Entity Address, Address Line One Room 1007
Entity Address, Address Line Two 10/F
Entity Address, Address Line Three Capital Centre
Entity Address, Address Line Four 151 Gloucester Road
Entity Address, City or Town Wan Chai
Entity Address, Country HK
Entity Address, Postal Zip Code 00000
Title of 12(b) Security Class B ordinary shares, par value $0.0001 per share
Trading Symbol BMHL
Security Exchange Name NASDAQ
Entity Well-known Seasoned Issuer No
Entity Voluntary Filers No
Entity Current Reporting Status Yes
Entity Interactive Data Current Yes
Entity Filer Category Non-accelerated Filer
Entity Emerging Growth Company true
Elected Not To Use the Extended Transition Period false
Document Accounting Standard International Financial Reporting Standards
Entity Shell Company false
Entity Common Stock, Shares Outstanding 25,000,000
ICFR Auditor Attestation Flag false
Document Financial Statement Error Correction Flag false
Auditor name FundCertify CPA Professional Corporation
Auditor Firm ID 7189
Auditor Location Cary, North Carolina
Business Contact [Member]  
Entity Addresses [Line Items]  
Entity Address, Address Line One Room 1007
Entity Address, City or Town Wan Chai
Entity Address, Country HK
Entity Address, Postal Zip Code 00000
City Area Code 852
Local Phone Number 2137 2688
Contact Personnel Name executive offices