Test approvals, failures and deployment
Run a reproducible test matrix and separate sandbox evidence from production readiness.
Use the sandbox only
NMI sandbox accounts do not move real money and are already in test mode. Use the documented test instruments below. A successful test proves your application handled a simulated outcome; it does not establish production processor approval, device certification or funding behavior. Instrument Test value Visa 4111111111111111 Mastercard 5431111111111111 Discover 6011000991300009 American Express 341111111111111 Expiration 10/29 ACH account / routing 24413815 / 490000018
Exercise the negative path
Use the same order and status UI customers will see. Capture redacted evidence for each scenario, including the gateway ID when one is returned. Scenario Documented trigger or application test Expected application behavior Approval Valid sandbox card, amount 10.00 Persist approval and transaction ID Decline Amount less than 1.00 No paid confirmation Invalid card Invalid card number Usable validation or failure feedback AVS match address1 = 888; zip = 77777 Inspect returned AVS result CVV match cvv = 999 in hosted fields Inspect returned CVV result Interrupted response Simulate a client/server network interruption Uncertain state and reconciliation path Repeated submit Click twice or submit from two tabs Application prevents competing attempts
Test 3DS separately when enabled
Use the issuer-authentication flow and test each result, including challenge cancellation. The following are NMI’s Visa 3DS test cards. Authentication success must still be followed by a payment request and payment-result handling. Visa test card Authentication behavior 4100000000000100 Frictionless 4100000000005000 Challenge 4100000000300005 Bypassed
Recurring sandbox has a specific limitation
You can create plans and subscriptions in sandbox, but the Recurring Module does not submit scheduled transactions there. Do not mark recurring charge processing tested merely because subscription creation succeeded. Test subscription state and your application’s event handling separately, and arrange a controlled production validation through the approved launch process. Sandbox recurring plans and subscriptions do not generate actual scheduled transactions.
Production readiness checklist
Promotion is a coordinated deployment, not a global search-and-replace of the hostname. Confirm merchant approval, processor route, currency and enabled methods. Replace both public and private sandbox keys with the matching production merchant credentials. Set the production host in server-only configuration and enforce HTTPS. Verify duplicate prevention, uncertain-outcome recovery, refunds and reconciliation. Review access, retention, logging and support ownership. Record approved production validation steps and a rollback plan before activation. Prepare for launch