Certificates of coverage are the forms that SSA and the Czech authorities issue to
            workers who would otherwise have to pay social security taxes to both countries on
            the same earnings. A certificate issued by one country serves as proof that the worker
            named on the certificate is:
         
         
            - 
               
                  • 
                     subject to the social security taxation and coverage laws of the country issuing the
                        certificate, and
                      
 
 
- 
               
                  • 
                     exempt from such laws on the same earnings in the other country.