How do I add a discount to an invoice?

This article explains how to discount an invoice.

To discount an invoice, navigate to your client's profile page and scroll down to the Invoices section on the right side of the page. Here you'll see the invoices that are currently due. To view past invoices, click See all invoices.  

Once you've found the invoice you wish to discount, click Update on the invoice. On the invoice page, you'll see a button labeled ADD DISCOUNT on the invoice. Click that button to add a discount.

Here you can specify the amount of the discount and a reason for providing a discount.

When you're done, click Add Discount to add the discount to your client's invoice. Once the discount is added it will be reflected as a line item in your client's invoice and the total amount due on the invoice will be calculated automatically.