Use the current identifier without losing historical references
Hong Kong adopted the Business Registration Number as the Unique Business Identifier for entities administered by the Companies Registry. The BRN generally corresponds to the first eight digits of the business registration certificate number, while older documents may display a former company registration number. Use the Registry’s official mapping facility to connect these references. Do not reject an older certificate solely because its number follows the previous system.
Match the identifier to the document and issuing authority
A shared identifier does not make incorporation records and business registration documents identical. The Companies Registry and Inland Revenue provide different services, so identify which certificate or extract your recipient needs. Some legacy entities have special identifier arrangements explained by the Registry. Check the complete legal name, document type and relevant number together before ordering a copy, and preserve the old reference when it helps trace historical filings.