Card Verification

Verify a card’s validity without charging the customer using zero-amount authorization.

Overview

Card verification allows you to confirm that a card is valid, active, and belongs to the customer without processing an actual charge. This is done through a zero-amount authorization (also called a $0 auth or account verification), where the issuer validates the card details and returns an approval or decline without reserving or capturing any funds.

Use Cases

Use Case	Description
Card enrollment	Verify a card before saving it for future use
Subscription signup	Confirm card validity before starting a free trial
Wallet top-up	Validate a card before linking it to a digital wallet
Pre-authorization check	Ensure a card is active before a high-value transaction
Fraud prevention	Detect stolen or invalid cards early in the flow

How It Works

1. Submit a verification request with the card details (or a vaulted token).
2. Yuno sends a zero-amount authorization to the card issuer.
3. The issuer validates the card number, expiration, CVV, and account status.
4. A verification result is returned: VERIFIED or FAILED with a reason code.
5. No charge appears on the customer’s statement (some issuers may show a temporary $0 hold).

API Example

cURL

curl --request POST \
  --url https://api.y.uno/v1/card-verifications \
  --header 'Content-Type: application/json' \
  --header 'X-Api-Key: YOUR_API_KEY' \
  --data '{
    "payment_method": {
      "type": "CARD",
      "token": "tok_card_abc123"
    },
    "country": "BR",
    "currency": "BRL",
    "customer": {
      "email": "[e-mail]"
    }
  }'

Verification Results

Status	Description	Next Step
VERIFIED	Card is valid and active	Safe to save or use for payments
FAILED	Card is invalid, expired, or declined	Prompt customer for another card

Failure Reasons

Reason Code	Description
CARD_EXPIRED	Card has passed its expiration date
CARD_DECLINED	Issuer declined the verification
INVALID_CARD_NUMBER	Card number fails Luhn check or is not recognized
CVV_MISMATCH	CVV does not match issuer records
INSUFFICIENT_FUNDS	Not applicable for $0 auth (rare)
LOST_OR_STOLEN	Card reported as lost or stolen

Some issuers do not support zero-amount authorizations and will decline the request. In these cases, consider using a small-amount authorization (e.g., $1.00) followed by an immediate void. Check with your provider for issuer support.

AVS and CVV Results

Card verification responses include Address Verification System (AVS) and CVV check results when available:

Result	Meaning
MATCH	Data matches issuer records
NO_MATCH	Data does not match
NOT_CHECKED	Issuer did not perform the check
UNAVAILABLE	Issuer does not support this check

AVS results require the customer’s billing address to be included in the verification request. Without address data, AVS will return NOT_CHECKED.

Best Practices

• Verify before vaulting: Always verify a card before saving it for recurring use.
• Handle failures gracefully: Provide clear error messages when verification fails.
• Use with 3DS: Combine card verification with 3D Secure for subscription enrollments.
• Do not over-verify: Excessive verification requests on the same card may trigger issuer fraud alerts.
• Inform customers: Some issuers show a temporary $0 pending charge. Consider informing customers that this is a verification, not a charge.