When you register a company in Serbia, you will get ID number of the company and Tax ID number of the company. When somebody says company registration number Serbia, he usually thinks on ID number of the company.
You can search for Serbian companies on official website of Serbian Business Registers Agency (SBRA) or on some pages as Bisnode Search.
On SBRA website, you can search for companies in Serbia using ID number or using name of the company. On Bisnode website, you can search by multiple criteria, even using Tax ID number.
On example, our company registration number is 20242728.