A register number identifies a register sheet within its register context. Keep it together with the register type and responsible court when researching a company.
Use the full reference
A bare number is not a reliable nationwide search key. Copy the register abbreviation and court as well. If references differ, check the source documents and their dates.
A useful research note
Record the full company name, legal form, court, register type and number. This helps associate later documents with the same research, even when other paperwork abbreviates the company name.
Example and different identifiers
A reference such as “Amtsgericht Musterstadt, HRB 12345” combines court, register section and number. This is a fictional example. Tax numbers, VAT IDs and insolvency case numbers are different identifiers. A change of register court may result in a new register number.