Buying food does not automatically earn a supermarket bonus. The merchant category reported with the transaction, together with the issuer’s rules, determines which reward rate applies.
Start with the store, not the shopping basket.
For the grocery bonuses modeled here, keep eligible supermarkets separate from superstores and warehouse clubs. Capital One’s Savor terms exclude superstores such as Walmart and Target. Amex’s supermarket definition excludes superstores and warehouse clubs. Capital One source ↗ · Amex category definitions ↗
Put qualifying supermarket purchases in Groceries. Put Walmart, Target, and warehouse-club purchases in Everything else. This conservative grouping does not model special checkout methods or store-specific exceptions.
A small classification change can move the result.
Suppose $300 per month was entered as groceries earning 3%, but actually earns a hypothetical card’s 1% base rate. The estimate would be too high by $300 × 12 × (3% − 1%) = $72 per year. On a flat 2% card, moving that purchase between categories does not change the estimate.
Don’t count the same purchase twice.
An online supermarket order belongs in Groceries if it meets the relevant supermarket rules. It should not also go in Online retail. If the merchant category is uncertain, use Everything else until you check a posted transaction or ask your issuer.
What about delivery and digital wallets?
Do not assume a delivery app or payment method preserves a supermarket category. Amex notes that third-party processing can prevent a purchase from receiving a bonus. The posted rewards on your own account are the useful check; our estimate cannot inspect a merchant’s coding. Read Amex’s merchant rules ↗