Why do I need to have a verified account for a free addon or custom domain?

Issue

You have tried to add a free third party addon or custom domain but have been rejected due to having an 'unverified' account.

Resolution

Credit card verification is a security requirement for the use of third party addons and custom domains. You will not be billed for using them even if you have your credit card information on file.

Further details can also be read here.