BRN, CRN, UBI: Which Number Actually Matters for Your Hong Kong Company in 2026?
- Jun 8
- 3 min read
If you've looked closely at your Hong Kong company's certificates recently, you may have noticed more than one number attached to your business and it's not always obvious which one you're supposed to use where. Since Hong Kong rolled out its Unique Business Identifier (UBI) system, this has become one of the more common points of confusion for founders, especially those managing filings from overseas.
Three numbers, three purposes
Every Hong Kong private limited company can have up to three reference numbers attached to it:
CRN (Company Registration Number): issued by the Companies Registry, this identifies the company as a legal entity under the Companies Ordinance.
BRN (Business Registration Number): an 8-digit number issued by the Inland Revenue Department when a business registers, used to identify it for tax purposes.
UBI (Unique Business Identifier): since 27 December 2023, the BRN has been adopted as the UBI across Hong Kong government departments, meaning the same 8-digit number now doubles as the single cross-agency identifier for your company.
For companies incorporated on or after 27 December 2023, the BRN/UBI is the number that appears as the "No." on the Certificate of Incorporation itself, so these companies effectively lead with the BRN from day one. For companies incorporated before that date, the original CRN still appears on the existing Certificate of Incorporation and remains valid, but the BRN/UBI is now the number the Companies Registry, the IRD, and other departments use as the primary cross-referencing identifier.
Why this matters in practice
This isn't just a naming exercise. Using the wrong number on a filing can cause delays or rejected submissions, and the two numbers genuinely serve different functions:
Tax matters and Business Registration Certificate renewals use the BRN/UBI.
Companies Registry filings reference the BRN/UBI (and, for companies incorporated before December 2023, the CRN alongside it).
Government electronic search services now use the BRN as the key identifier for finding and confirming a company's status.
For companies that don't have a BRN on record at all — such as certain entities exempt from business registration — the Companies Registry has assigned a "dummy" BRN so every entity has a UBI, even if it doesn't correspond to an actual business registration.
What founders and finance teams should actually do
If you're filing anything with the Companies Registry, the IRD, or opening or maintaining a bank account, it's worth confirming which number the form or counterparty actually wants before you submit. In practice:
Use the BRN/UBI for tax filings, Business Registration Certificate renewals, and most Companies Registry electronic search functions.
Keep the CRN on hand if your company was incorporated before December 2023 — it still appears on your original Certificate of Incorporation and remains relevant for some statutory references.
Double-check both numbers match across your certificates, your bank's records, and any compliance documentation, particularly if you're dealing with counterparties running their own KYC or supplier verification checks.
Keeping this straight without the guesswork
For companies without a Hong Kong-based team tracking regulatory changes like this one, small identifier mix-ups can snowball into rejected filings or delayed bank processes. This is exactly the kind of detail a company secretary is meant to manage as part of ongoing compliance, rather than something a founder should have to piece together from government circulars.
Want a Hong Kong company secretary who keeps your filings, numbers and statutory records correctly aligned? Book a free consultation with our team
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Woodburn Accountants & Advisors is specialized in inbound investment to China and Hong Kong. We focus on eliminating the complexities of corporate services and compliance administration. We help clients with services ranging from trademark registration and company incorporation to the full outsourcing solution for accounting, tax, and human resource services. Our advisory services can be tailor-made based on the companies’ objectives, goals and needs which vary depending on the stage they are at on their journey.
