Why did I get a link invite email that was asking me to register when I already have an account?
This happens when the client invites you by email but uses a different email address to the one you used for registering. Often this is either to a personal email address or an email address for the business (e.g. info@example.com like email).
We recommend just inviting them back from your account (if you know their email adresss) or asking them to invite you by link code.

