Costco accepts Mastercard, but only if you have a Costco membership and shop at a warehouse location

Costco takes Mastercard at its warehouse locations, both in-store and online. However, Costco's payment rules are stricter than most retailers. You must be a member to shop there, and Costco limits which payment methods work depending on where you shop — warehouse versus Costco.com versus the Costco Gas Station.

The short version: Mastercard works at Costco warehouses and on Costco.com. Visa, American Express, and Discover also work. Diners Club works at warehouses only. Cash, debit cards, and Costco's own Costco Anywhere Visa card work everywhere. What does not work: personal checks (warehouses only accept them at membership desk), and most store credit cards from other retailers.

Key Takeaways

  • Mastercard is accepted at Costco warehouse locations and on Costco.com, but you must have an active Costco membership to shop.
  • Costco Gas Stations accept Visa only — not Mastercard, American Express, Discover, or Diners Club.
  • The Costco Anywhere Visa card (their branded card) works everywhere Costco operates, including gas stations.
  • Costco.com accepts the same credit cards as warehouses: Visa, Mastercard, American Express, Discover, and Diners Club.
  • If your Mastercard is declined, the most common reason is an expired membership or a card flagged for fraud — call Costco member services to check.

Mastercard at Costco warehouse locations

Mastercard works at Costco warehouse checkouts. You can use any Mastercard — personal, business, or prepaid — as long as the card is active and your membership is current. Costco does not restrict which bank issued the Mastercard or what type of rewards it carries.

The membership requirement is non-negotiable. If your membership has expired or lapsed, your Mastercard will be declined at checkout even if the card itself is valid. Costco checks membership status at the register before processing any payment. If you are unsure whether your membership is active, ask a cashier or check your membership card — it shows an expiration date.

Costco Gas Station payment rules are different

Costco Gas Stations accept Visa only. Mastercard does not work at the pump or at the gas station attendant window. This is a hard rule across all Costco Gas locations in the United States and Canada.

The exception is the Costco Anywhere Visa card, which works at gas stations because it is a Visa product. If you want to pay with Mastercard at a Costco Gas Station, you would need to go inside the warehouse and pay at the membership desk, which is not a practical option. The simpler solution is to use a Visa card, debit card, or cash at the pump.

Costco.com accepts Mastercard for online orders

Mastercard works on Costco.com for both members and non-members. You do not need a warehouse membership to order from Costco.com, though some items are member-only and will not appear in your cart unless you have an active membership.

Costco.com also accepts Visa, American Express, Discover, and Diners Club. You can save your Mastercard to your account for faster checkout on future orders. If you use a Mastercard linked to a rewards program, those rewards post to your card issuer's account, not to Costco — Costco does not track or match rewards from outside cards.

Why your Mastercard might be declined at Costco

If your Mastercard is declined at a Costco warehouse, the most common reasons are: your membership has expired, your card issuer flagged the transaction as suspicious, or the card itself is expired or has insufficient funds. Ask the cashier to try the card again — sometimes a temporary processing error causes a single decline.

If it declines twice, call your Mastercard issuer from the store or ask Costco member services to check your membership status. Membership lapses are the single most common reason for payment failure at Costco. If your membership is current and your card is active, the issue is almost always on your card issuer's side — they may have blocked the transaction due to fraud detection or because you have not used the card recently.

Other payment methods that work at Costco

Costco accepts Visa, American Express, and Discover at warehouses and online. Diners Club works at warehouses only, not online or at gas stations. The Costco Anywhere Visa card (Costco's branded credit card) works everywhere: warehouses, online, and gas stations.

Debit cards and cash work at all Costco locations. Personal checks work at the membership desk in warehouses only — not at regular checkout and not at gas stations. If you want to use a check, bring it to the membership desk and ask a staff member to process it.

Costco Anywhere Visa card versus other Mastercard options

If you shop at Costco frequently and want to use a rewards card, the Costco Anywhere Visa card is the only Costco-branded option. It earns 2% cash back on Costco purchases, 1% on other purchases, and works at Costco Gas Stations (where Mastercard does not). The card is issued by Visa, not Mastercard, so it does not help if you specifically want to use a Mastercard.

If you prefer Mastercard for rewards or other reasons, you can use any Mastercard at Costco warehouses and online. Your rewards post to your Mastercard account, not to Costco. Costco does not offer a Mastercard-branded card and has no partnership with Mastercard issuers, so there is no Costco-specific Mastercard product.

Frequently Asked Questions

Can I use Mastercard at Costco Gas Station?

No. Costco Gas Stations accept Visa only. Mastercard, American Express, Discover, and Diners Club are not accepted at the pump. The Costco Anywhere Visa card works at gas stations because it is a Visa product.

Do I need a Costco membership to use Mastercard at the warehouse?

Yes. Costco checks membership status at checkout before processing any payment. If your membership has expired, your Mastercard will be declined even if the card is valid and has funds available.

Does Costco.com accept Mastercard?

Yes. Costco.com accepts Mastercard, Visa, American Express, Discover, and Diners Club. You do not need a warehouse membership to order from Costco.com, though some items are restricted to members only.

What should I do if my Mastercard is declined at Costco?

First, check that your membership is current — expired membership is the most common reason for decline. If your membership is active, call your Mastercard issuer to see if they blocked the transaction for fraud protection. Ask the cashier to try the card again, as temporary processing errors sometimes cause a single decline.

Is there a Costco Mastercard?

No. Costco offers only the Costco Anywhere Visa card, which is issued by Visa. There is no Costco-branded Mastercard. You can use any Mastercard at Costco warehouses and online, but it will not earn Costco-specific rewards.