Yes, you can use a Costco Reward Certificate online, but with one important limit
Costco Reward Certificates can be used for online purchases at Costco.com, but only toward the final payment step—you cannot redeem them during checkout the way you would in a warehouse. Instead, you'll complete your order, reach the payment page, and then enter the certificate number to reduce what you owe. The certificate applies to your total purchase, including items and shipping, but not to membership fees if you're renewing at the same time.
If your certificate has a remaining balance after one purchase, that balance stays active in your account and you can use it on future orders. Costco does not issue refunds for unused portions of certificates, so the balance straightforward carries forward until it's fully spent.
Key Takeaways
- Costco Reward Certificates work online at Costco.com by entering the certificate number at the payment page, not during the shopping cart step.
- The certificate reduces your total order cost, including shipping, but cannot be applied to membership renewal fees charged at the same time.
- Any remaining balance on the certificate stays in your account for future purchases and does not expire.
- You can also use the same certificate in a Costco warehouse by showing it at checkout or giving the number to the cashier.
- If you lose track of your certificate number, you can find it on your Costco account under the rewards or certificates section.
How to enter your certificate number at checkout
When you reach the payment page on Costco.com, look for a field labeled "Reward Certificate" or "Gift Certificate." Click into that field and type the 16-digit certificate number printed on your physical certificate or shown in your Costco account. The system will when ready deduct the certificate value from your order total.
If the certificate value is larger than your order total, the remaining amount stays on the certificate. You do not receive the difference as a refund or store credit—it straightforward remains available for your next purchase. If your order total is larger than the certificate value, you'll pay the difference using your regular payment method (credit card, debit card, or linked bank account).
What happens if you can't find your certificate number
Log into your Costco.com account and look for a "Rewards" or "My Account" section. Most accounts display active certificates with their numbers and remaining balances. If you received a physical certificate in the mail, the 16-digit number is printed on the front. If you still cannot locate it, contact Costco member services by phone or through the website—they can look up certificates tied to your membership number.
Do not share your certificate number with anyone else, as it functions like cash once someone has the number. If you believe your certificate number has been compromised, contact Costco when ready so they can issue a replacement.
Using the same certificate in the warehouse
A single Costco Reward Certificate works both online and in-warehouse locations. You can split the balance between the two if you want—use part of it online and the rest in person. At the warehouse, straightforward hand the physical certificate to the cashier at checkout, or tell them the certificate number and they can enter it into the register.
The warehouse cashier will see the remaining balance on the certificate and deduct it from your purchase. If your purchase is smaller than the certificate value, the leftover amount stays active and you can use it on a future warehouse visit or online order.
Certificates that cover the full order versus partial amounts
Some Costco Reward Certificates are issued for a specific dollar amount—$25, $50, or $100 are common values. Others may be promotional certificates with different amounts. Regardless of the value, the process is the same: enter the number at checkout and the full available balance applies to your order.
If you have multiple certificates, you can only enter one per online order. To use a second certificate, you would need to place a separate order. In the warehouse, you can ask the cashier to explore multiple certificates to a single transaction if you have them.
Common mistakes to avoid when redeeming online
The most frequent error is entering the certificate number in the wrong field or at the wrong step. The certificate field appears on the payment page, not in the shopping cart or shipping address section. If you enter it too early, the system will not recognize it. Always wait until you reach the final payment screen.
Another common issue is forgetting that membership renewal fees cannot be paid with a Reward Certificate. If you're renewing your membership and placing a product order at the same time, the certificate will reduce the product total but not the membership fee. You'll need a separate payment method for the membership portion.
Do not assume the certificate has expired just because you haven't used it in a while. Costco Reward Certificates do not have expiration dates printed on them. As long as your membership is active, the certificate remains valid. If your membership lapses, you may lose access to the certificate, so renew your membership if it's about to expire.
What to do if the certificate doesn't work at checkout
If you enter the certificate number and the system rejects it, first double-check that you've typed all 16 digits correctly. Certificate numbers are case-sensitive in some systems, so verify each character. If the number is correct and the system still rejects it, the certificate may have already been fully redeemed on a previous order.
Contact Costco member services with your certificate number and order details. They can confirm whether the certificate has a remaining balance and troubleshoot why it's not working. If the certificate was damaged or lost in the mail, they can issue a replacement. Response times vary, but most issues are resolved within one business day.
Frequently Asked Questions
Can I use a Costco Reward Certificate to pay for my membership renewal?
No. Reward Certificates reduce the cost of products and shipping, but membership fees are charged separately and must be paid with a credit card, debit card, or bank account. If you're renewing and buying products in the same transaction, the certificate applies only to the product portion.
What if my certificate balance is larger than my order?
The remaining balance stays on the certificate and you can use it on future purchases. Costco does not refund the difference or convert it to store credit. The certificate straightforward carries the lower balance forward until it's fully spent.
Do Costco Reward Certificates expire?
No, they do not have an expiration date. As long as your Costco membership is active, the certificate remains valid. If your membership lapses, you may lose access to the certificate, so keep your membership current if you have an unused balance.
Can I use multiple certificates on one online order?
No, the online system accepts only one certificate per order. If you have multiple certificates, you can place separate orders for each one, or use the additional certificates during a warehouse visit where cashiers can explore multiple certificates to a single transaction.
Is there a way to check my certificate balance without logging in?
You need to log into your Costco.com account or contact member services by phone to check your balance. The certificate number alone does not display the balance—you must verify it through your account or by calling Costco directly.