Why your grocery card earns 1x at Walmart
Walmart Supercenters typically code as discount stores (MCC 5310), and grocery bonuses pay on supermarkets (MCC 5411). American Express lists superstores "e.g., Target, Walmart" as not counting, and Chase excludes "larger stores that sell a wide variety of goods and groceries like Walmart and Target."
So a Blue Cash Preferred that pays 6% at a supermarket pays 1% on the same groceries at a Supercenter, and an Amex Gold's 4x becomes 1x. The table above scores every card that way. Some Walmart stores, including Neighborhood Markets, are reported to code as supermarkets, so check your statement before assuming either way.
The math on $4,000 a year
A household that spends about $330 a month at Walmart, $4,000 a year, gets:
| Card | Rate at Walmart | Per year |
|---|---|---|
| OnePay with Walmart+ | 5% | $200 |
| OnePay without Walmart+ | 3% | $120 |
| No-fee 2% card | 2% | $80 |
| Grocery card at a Supercenter | 1% | $40 |
Even without Walmart+, the OnePay card beats a 2% card by $40 a year at that spend. With Walmart+ the gap is $120, which covers part of the membership if you'd pay for it anyway.
Where OnePay falls short
Outside Walmart the card pays 1.5%, less than a no-fee 2% card. Treat it as a Walmart card and use something else for everything else. If you already hold a card that earns more on your other spending, adding OnePay just for Walmart costs nothing to hold.