Can I apply my FLX Cash reward to an earlier purchase? No, you cannot. FLX Cash does not apply to prior orders and can only be used at checkout. Related articles The item I want is marked “excluded from discount.” Can I use FLX Cash to pay for it? Privacy Statement Can I combine an FLX Cash reward with another discount? Can I remove an FLX Cash reward from my purchase? How do I manage my FLX Rewards account?