SSL Certificates that we provide could be issued either for a domain name/sub-domain or multiple domains or for a bare domain name along with all the sub-domains of a specified level in case of WildCard Certificates. Each Certificate requires a dedicated IP assigned to the domain name for proper installation and functioning of the Certificate. In case SNI Technology is available for your server type, the Certificate can be installed on a shared IP address.
Nevertheless, a certificate does not contain any information about an IP address, and an SSL session is not bound to any specific IP address. If the IP address is the only thing that needs to be changed, reissue of the certificate is not obligatory. You just need to be sure that a dedicated IP to which your domain name resolves should not be used for the installation of any other Certificate (unless you use SNI). A dedicated IP can be purchased from your Hosting Provider. If you change the IP address, you might need to re-install the Certificate though. You can always check how accurate your installation is here.