You can attach coupons to your invoices to offer discounts and encourage your customers to pay promptly. You can create coupons and then enable the coupons plugin for your invoice format.
To know more about creating coupon codes, read...
Add discount coupons to invoices
To add coupons to invoice by enabling the Coupons plugin, navigate to Collect Payments -> Create Invoice -> Select Format/Edit Format or create a new invoice format.
Scroll down to the Plugins section and click on Choose Plugins button. Switch the toggle against the Coupon plugin to On and close the plugins window.
Click on the Save button in the Final summary section and the Coupon plugin will be added to the invoice template.
Creating an invoice with coupons
When creating an invoice using this invoice format, you can select coupon from the drop-down list available in the Plugins section. The drop-down list contains the different coupons you have created to be applied by your customer while making a payment to avail a discount.
You can also create a new coupon coupon by clicking on the Add new coupon button. To know more about creating coupons read...