Hi!

I'm assuming a couple of things here: moderately new Commerce version, new promotion system.

You don't need to do anything for the built in promotions/discounts to work, you just need to set them up and then run promotions on your cart.

I made a checklist last week that can help you debug why a promotion isn't showing. Take a look at that and report back if you find anything :)

AppSettings, no, but code, yes. Make sure you don't have such code in your initialization (or anywhere) 

var promotionTypeHandler = context.Locate.Advanced.GetInstance<PromotionTypeHandler>();

// To disable all built-in promotion types.
promotionTypeHandler.DisableBuiltinPromotions();

Thanks Quan, there is a DisableBuiltinPromotions() call this should solve my problem.

Thanks Joel, I got your site before reading your comment, very nice writeup :-)

Seems like I need to add another point though ;) Even though I think this is one of the very rare cases as well, seeing as you (or someone) need to add the DisableBuiltinPromotions(); manually in your solution in order to not find them :D

You probably should. However I don't think this is a very rare case. We added that feature because customers asked for it, so it might be more common than you think ;)