After inputting the first contact’s information you can add multiple customers at the same time. Click the link ‘+add another contact’.
Toward the bottom of the page, the option to add another contact will be there. Once you’ve added these details remember to click the green create contact button to add the contact to your database.
There is no limit to how many contacts can be added at any time, although in practical terms you'll likely not being adding lots at the same time.
When you're adding multiple contacts the title '2nd contact' will be presented.