Coupon vs Cashback: the stacking census.

What the census shows.

Code only, cashback only, or both.

Each scenario below uses a real merchant's coupon policy and its headline rate from the 2026-08-13 rate-index edition, applied to a stated hypothetical order and code. Every dollar figure is arithmetic on those stated inputs, so it can be re-derived from the table.

The pattern generalizes: where featured codes stack, the discount applies first and cashback is earned on the discounted price, so stacking beats either saving alone. Where any code voids cashback, the better option is whichever single saving is larger for that order, which flips with order size and rate.

How travel merchants treat codes.

Travel is the sharpest illustration of why the policy matters: booking values are high, so a voided cashback payout costs more than it would on a typical retail order. 16 of the 18 tracked travel merchants stack ShopBack-featured codes, while 2 void cashback whenever any code is used. The Travel Cashback Rate Index reports what those travel rates pay by segment.

Every merchant's coupon policy and rate.

The complete policy-by-rate table, strictest policies first. Rates are the headline figures from the 2026-08-13 rate-index edition; the live, binding rate for any store is the one on shopback.com.

How this study is built.

The study classifies every real US merchant published on this site into one of three coupon-policy classes, based on the merchant's terms on its shopback.com store page: featured codes stack, any code voids cashback, or the merchant warns its own codes can void cashback. It is a census, not a sample: every tracked merchant is included and none is chosen or dropped, so the proportions describe the whole tracked network. Rate figures quoted alongside policies come from the dated rate-index edition stated in each table, and scenario dollar figures are arithmetic on stated hypothetical inputs. Shares are rounded to one decimal place. Classifications are re-verified when merchant terms change; the study's stated date is the newest verification date, and a factual error is corrected with a dated note rather than a silent edit. No competitor or third-party data is used: every classification comes from first-party reading of ShopBack's own published terms.

Common questions about the study

What does the Coupon vs Cashback study measure?

It classifies how every merchant tracked on this site treats coupon codes alongside ShopBack cashback, based on each merchant's published ShopBack terms: whether ShopBack-featured codes stack, whether any code voids the cashback, or whether the merchant warns its own codes can void it. The study reports the share of merchants in each class and worked examples of what each policy is worth in dollars.

Is the study based on a sample of merchants?

No. It is a census of every real merchant published on this site, so the proportions describe the whole tracked network. No merchant is excluded or selected for effect.

Do coupon codes usually void cashback?

At most tracked merchants, codes featured on ShopBack stack with cashback while codes from elsewhere can void it. A smaller group of merchants voids cashback whenever any code is used, and a few warn that even their own codes can void it. The per-merchant table on this page lists every policy.

Is stacking a code with cashback ever the best value?

Often, yes. Where a ShopBack-featured code stacks, the discount applies first and cashback is then earned on the discounted price, which beats either saving alone. Where any code voids cashback, the better option is whichever single saving is larger for that order.

Where do the policy classifications come from?

From each merchant's terms on its ShopBack US store page, the same source that powers the terms highlights on this site's merchant reference pages. Classifications are re-verified when merchant terms change, and the study's stated date is the newest verification date.

Keep reading.

The study pairs with the stacking guide for the step-by-step playbook, the Travel Cashback Rate Index and US Cashback Rate Index for what the rates pay, and the How Cashback Works explainer for the tracking rules behind every policy.