At the moment, discounts can only be applied on the invoice page. And yes, we can keep the invoice amount unchanged until the customer is ready to pay and then apply the discount, agarcia1.
You still have full control over when to apply the discount to the invoice. Here's how to manage it:
- Open the invoice you want to keep unchanged.
- Click Manage and go to the Payment options section.
- Under More options, disable the Discount feature.
- Select Save and close. You can also send it to the customer if needed.

If the customer pays the invoice earlier than the due date, you can return to the Payments options section and enable the Discount feature. At this point, you can set the appropriate discount percentage or amount directly on the invoice.

Once you've applied the discount, you'll be able to record the invoice payment reflecting the exact amount received from the customer.
Feel free to reach out if you have any other concerns.