Promo codes in Infusionsoft are case-sensitive. If you have a promo code named SummerSpecial but your customer types in summerspecial, it won’t apply the promo. To make things easier for your customers, create additional promo codes in all lowercase and all caps.
Infusionsoft doesn’t let you have multiple promo codes per promotion, so you’ll also need to create an additional promotion for each additional promo code.
