When you create a partner on the partners page, they will be invited to create a Maersk account, if they don't already have one. However, if you then choose to select a certain buyer or supplier for your booking, they will be notified automatically that you have chosen them to play a role in your bookings. They may then be asked to sign up on Maersk to perform certain actions. This will make sure the shipment goes smoothly and creates transparency for you in terms of seeing various deadlines, actions and statuses.