Can I use two Amazon promo codes on the same order?
No. Amazon accepts one promotional code per order. Use the code with the highest value, and layer everything else (clip coupons, Subscribe & Save, gift cards, cashback) around it.
Do clippable coupons count as a promo code?
No. Clip-to-account coupons apply automatically at checkout and don't touch the "promotional codes" field, so they stack freely with a real promo code.
Does Subscribe & Save stack with a promo code?
Yes on most eligible items. Subscribe & Save is treated as a per-item discount, not a promotional code, and the two combine at checkout.
Is a gift-card discount really a "stack"?
Effectively, yes. A gift card bought for 5% below face value acts like a 5% payment discount that Amazon can't refuse — it applies after every checkout discount is calculated.