An email address can only ever be attributed to one account. If you want to add an additional user to your Agency plan but they already have an existing account registered with that email address, they will need to request for their registered account to be deleted or alternatively update the email on their registered account to something else.

Ask the person to either request that their existing Paperform account be deleted at support@paperform.co, or ask them to change their email address in their existing account by going to paperform.co/account.

Once their email address is no longer attributed to an existing account, you will be able to successfully add them as a user on your Agency account.