Does cashback stack with credit cards? Yes, here's how

Short answer: yes, cashback stacks with credit card rewards, and it's one of the easiest ways to add a few extra percent to a large share of your online purchases. A shopping portal (a site that pays you cashback for starting your purchase there) and your credit card are two separate payments, from two separate companies, for one purchase.

How cashback stacks with credit card rewards

This is the "double dip." When you click through a portal and pay with a rewards card, two things happen:

1. The store pays the portal a commission for sending you, and the portal hands most of it to you as cashback.
2. Your card issuer pays you its normal rewards for the swipe, exactly as it always does.

Take Best Buy right now: TopCashback pays up to 16%, and a card like the Amex Blue Cash Everyday earns 3% back on U.S. online purchases (up to $6,000 a year, then 1%). Click through first, pay with the card, and you keep both, because the two are separate payments and simply add up.

Here are Best Buy's current portal rates below. Every other store works the same way: mentally add your card's earn rate on top of whichever portal you'd pick.

The one rule that makes or breaks it

Click through the portal first, then pay with the card. The order matters for the portal half (the cookie has to be set before you land on the store), and not at all for the card half (the card still earns as long as the purchase qualifies under its own terms). Miss the click-through and you simply drop back to card-rewards-only: still fine, just not stacked.

How far can you push it?

For most people, portal + card is the whole game, and it's plenty. If you like to optimize:

• A coupon code helps, but only the ones the portal itself surfaces. An outside code is one of the most common reasons a purchase fails to track at all.
• A gift card cuts both ways. Buying one through a portal is usually excluded from cashback (TopCashback excludes gift cards at Best Buy, for example), so check the portal's terms first. Paying with a gift card on your next order is a different move: typically it invalidates that purchase's portal cashback (Best Buy itself is one of the stores that blocks it), though sometimes it still works, so check before counting on it.

Want the full map of the stack, including gift cards, coupons, and card-linked offers? The stacking guide walks through all of it.

The takeaway

At a store a portal pays on, every purchase made without clicking through leaves the portal half of the stack on the table, and it costs one extra click to fix. Check the highest rates we've seen, pay with your best card, and let the two payments pile up.