Thawte SSL123 certificate does not require documentation. Make sure your domain's WHOIS information is correct and up-to-date. Thawte Web Server and Wildcard
certificates require any of tax certificate or "faaliyet belgesi" or "sicil tastiknamesi" or "ticaret sicil gazetesi örneği" for companies and
identity card or passport or driving licence for individuals. İn some cases, if the company can be verified in digital means, no documents may be required.
The steps that you need to follow is explained detailly in the email that is sent after registration.