Choose from any of our gift cards to give to your loved ones
Card Number Validation Techniques Guide
Redeem your gift cards at any of our Merchants
You can purchase a gift card from any of these locations
Onyx Gift Cards is a Grenadian company designed to introduce, market and manage gift cards systems in Grenada for retailers and corporations. We are enthusiastic about the effect and influence we will have on the local market. We intend to expand our systems regionally with a range of product offerings and services.
Gift cards are the preferred way of giving and receiving gifts. They carry a monetary value that can be redeemed for gifts at your favorite store.
Onyx GiftCards are “Open Gift Cards” which means that they can be redeemed at multiple merchant locations. They are standard credit card size, can fit into the average wallet and made of PVC plastic. Onyx GiftCards are Barcoded for security and safety for the consumer and bear a disclaimer at the back.
Onyx Giftcards can be bought with a branded Card backer which is black in colour and is designed to fit the card. There is an area to write a brief message to the recipient as well.
A card number validator checks the digits on a payment card number for format and a checksum. It returns pass or fail. It does not contact a bank. It does not prove the card exists, is active, or has funds.
Most validators run the Luhn algorithm, also called mod 10. The check doubles every second digit from the right. If a doubled digit is above 9, subtract 9. Sum all digits. The total must end in 0. A 16-digit Visa test number such as 4111 1111 1111 1111 passes. A single wrong digit fails.
Validators also check length and the leading digits, called the issuer identification number (IIN) or BIN. Visa numbers start with 4 and run 13, 16, or 19 digits. Mastercard uses 51 through 55 and the 2221 through 2720 range, at 16 digits. American Express starts with 34 or 37 and runs 15 digits. These rules come from ISO/IEC 7812.
About 1 in 10 random digit strings passes Luhn. The check catches typing errors. It does not catch fraud. Card numbers that pass Luhn can be closed, stolen, or fake. A validator cannot detect a card that was never issued.
Checkout forms run a Luhn check before a payment request. This catches mistyped digits and reduces failed authorizations. Payment gateways repeat the check on the server. Client-side validation alone is not a security control.
PCI DSS applies to any system that stores, processes, or transmits cardholder data. A validator that checks digits in a browser and keeps no record does not store data. Logging full card numbers does create scope.
