Error Codes

Every Checkout API error response returns a JSON object with the following fields:

Field	Type	Description
code	number	3-digit Verifone error code
timestamp	string	ISO 8601 timestamp of the error
message	string	Human-readable description
details	object	Optional additional context

When debugging a 400 error, always check the details field — it will identify which specific request parameter is invalid or missing.

Common Error Codes

400 Bad Request

Verifone Code	Cause
107	Invalid parameter format — check details for affected fields
110	Invalid resource or malformed JSON
126	Missing required parameter
123	Transaction rejected by processor
127	Unexpected parameter submitted

401 / 403

404 / 500 / 504

Checkout-Specific Codes

These codes are unique to the Checkout API lifecycle:

Session State Errors

• 165 — The session has exceeded 3 failed payment attempts. Create a new checkout session.

• 168 — The session has already been completed. No further payments can be made.

• 169 — The session has expired (sessions are valid for up to 30 days). Create a new checkout session.

Recommended Actions

• For 165 / 168 / 169: always create a fresh checkout via POST /v2/checkout

• For 100 server errors: log the full code and timestamp and contact Verifone support

• For 170 timeouts: implement an exponential back-off retry strategy