Adding a customer is really easy, you can do this one of three ways:
From any page, you’ll see a plus sign in the upper right, just hover over that and click customer. It’s going to open up a section on the right, where you can add the customer information.
If you go to the Customers page (Left), you can simply click add customer from the top right corner and it’s going to open up the same window.
You can also customers while working on an invoice. In the bill-to field, if you start typing in a customer’s name and there is no result, you can click add new customer and add it directly from the invoice.
When adding the customer, Add the customer name, and select the country. The address, phone number and fax are not mandatory fields although it’s good to add them.
The first name, last name and email are really important fields especially if you are going to be emailing your customers invoices. If you do not put in an email, you won’t be able to email your customers invoices. Click Save and you’re set!
(Free Plans have a limit of 3 customers, deleting old ones and creating new ones wont work)