NowCerts now has the ability to require approval on any certificate the Insured has sent out. To turn on this feature go to the client's account and under their user permissions select "Require Approval to Send Certificates".

Once your client sends out a certificate you will see a counter on the left-hand navigation menu and from this area of the certificate, you will see the option to approve the certificate.

Here is a video covering this.

Self-service certificate video