Coupon Code Accepted on Invoice

[DauntlessMV]

I would like to be able to send a coupon code to my remote customers as a thank you for completing a survey.   Could functionality be added to allow customers who are paying invoices to use the coupon code.  It would, clearly, need to be linked to an existing discount.

[CocktailswKay]

I need this feature! As a business that does private events (weddings, birthday parties, networking events, etc) and has custom prices depending on number of guests, hours, type of service requested, etc, allowing customers to use a coupon code for promotional discounts would be very beneficial to my business.