Test Transaction Card: Sandbox Numbers and How to Use Them

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Choose from any of our gift cards to give to your loved ones

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Redeem your gift cards at any of our Merchants

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What is ONYX GiftCards?

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.

What is a Gift Card?

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.

How it Works?

  • Buy an Onyx Gift Card at these local stores
  • Give your gift card to friends, family, co-workers, etc.
  • The recipient can shop at our select merchants nationwide
  • Your friends, family, co-workers, etc. will present their gift card at checkout to pay for your item(s)
  • They will walk away happy with the best gift ever...the gift of Choice

Why ONYX GiftCards?

  • Save TIME. No need to run around looking for the perfect gift
  • Redeem from a variety of business island-wide. We will continue adding businesses as fast as ONYX grows.
  • ONYX Gift Cards do not expire
  • Cards are valued at convinient amounts to meet every need and occasion

A test transaction card is a fake card number published by a payment processor for sandbox testing. It passes the same format checks as a real card, so the gateway accepts it and returns a scripted response instead of moving money.

Test cards exist so developers and merchants can exercise a checkout before going live. They work only in test mode and never in production.

What is a test transaction card?

A test transaction card carries a number that no bank issued and no cardholder owns. The gateway recognizes the number in its test environment and replies with the outcome you asked for.

Stripe, for example, uses 4242 4242 4242 4242 for a successful Visa charge and 4000 0000 0000 0002 for a generic decline. Other processors publish their own lists.

Every test number shares three traits: no account sits behind it, it works only with test API keys, and it produces the same result on every run.

Who publishes test transaction cards?

These numbers are public on purpose. They hold no value outside the sandbox, which is why a test card is useless for theft.

How do you run a test transaction?

  1. Create a sandbox account with your gateway and copy the test API keys.
  2. Point your checkout at test mode. Most gateways need a separate key, not a toggle.
  3. Enter the test card number, any future expiry date, and any 3 or 4 digit CVC.
  4. Submit the payment and read the response in the gateway dashboard.
  5. Confirm your app handles both the success path and the decline path.

Some gateways also accept test bank accounts for ACH transfers and test wallets for Apple Pay or Google Pay.

Which scenarios can you simulate?

Test cards cover the outcomes a live checkout will meet. Common ones:

Each processor maps one number to one result, and the mapping differs between providers. Read the docs for the exact list.

Why do test cards fail on live sites?

A test card number will not clear a live gateway. Live keys route to the card networks, where the number has no account behind it. The charge comes back as declined or invalid.

If a live storefront accepts 4242 4242 4242 4242 and shows a paid order without a real payment, that store is running in test mode by mistake. Merchants lose stock and revenue that way.

Test cards vs. real card data

Test numbers are synthetic and free to publish. Real card numbers, expiry dates, and CVV codes belong to cardholders and fall under PCI DSS.

Buying, selling, or trading real card data is carding, a criminal offense in the US and most other countries. Sites that advertise CVV sales are either illegal operations or scams that take a buyer's money and send nothing back.

If you need a full end to end check on a live gateway, use your own card for a small amount and refund it, or ask the processor for a certified test account.

What should you check before switching to live keys?

FAQ

Do test transaction cards work in production?

No. A test card number has no issuing bank behind it, so a live gateway rejects it. Test numbers function only with test API keys.

Can I get a test card from my bank?

No. Banks issue real cards tied to real accounts. Test cards come from payment processors, not from financial institutions.

Is a test card number personal data?

No. It identifies nobody and carries no account, balance, or credit line. It is a documentation sample, not a payment instrument.

Do I need a real CVV for a test transaction?

No. Sandboxes ignore the CVC value in most cases. A few test numbers exist to trigger a CVC mismatch on purpose so you can test that error path.

Why does my test card keep declining?

Three usual causes: you are using live keys, the number is mapped to a decline scenario, or the expiry date you typed is in the past. Check the key prefix first.

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Read our complete guide: Should You Buy CVV From a Card Shop? The Honest Buyer's Guide