If you see this error when trying to provision the account (add users to the Business license subscription), it means that all seats in your organization have been allotted.
As a workaround, we suggest removing inactive users from the subscription or voiding pending invitations to free up existing seats.
Another option is to purchase additional seats for your license. If you'd like to purchase additional seats instead, please contact your account representative from our Sales department for further assistance or email sales@grammarly.com.