Domain control validation for TLS certificates

Before a CA can issue you a TLS certificate, you must prove that you control the domain secured by that certificate. This is called Domain Control Validation (DCV). Once the CA validates domain control, it can proceed to create and issue the certificate during the valid lifetime of the certificate.

DCV is the most difficult part of automation and the one changing the most. Many legacy DCV methods involve manual procedures such as email or phone calls, but these are all being phased out under the current standards.