Registry code
A registry code is an eight-digit number assigned by the Estonian Business Register to every company, association, foundation, and branch. The code is unique, never changes, and stays with the entity for its entire life — even after the name, legal form, or ownership changes.
Difference from a VAT number (KMKR-nr): the VAT number is issued only when a company registers for VAT (typically when annual turnover exceeds €40,000). Not every registry-code holder has a VAT number.
In practice the registry code is used in every formal document — contracts, invoices, court cases, KYC procedures. URLs on firmaotsing.ee are built around it: /firma/12417834 always points to one specific company.