Once your instrument is close to being ready to ship, you will receive an automated email from contact[at]expressivee.com inviting you to pay the remainder. Feel free to white-list (add to trusted senders) this email address so you are sure it won't get stuck in your spam folder.
Once you have been invited, an add-to-cart button will be unlocked below the red reservation banner inside your customer account.
A few days later, you will also receive separate reminder emails from the personal email account of our head of customer support. Those are less likely to end up in spam.
To ensure that you don't miss out, we recommend logging into your account occasionally to check if the red reservation banner shows updated information.