Every sandbox payment I make succeeds. I need to test what my code does when a payment fails, times out, or the customer has no money.
Is there a way to force those, or do I just have to hope it happens in production?
You never have to hope. The simulator is deterministic, and the last digits of the phone number choose the outcome.
| Test MSISDN ends with | What happens |
|---|---|
700000001 |
succeeds |
700000002 |
fails, insufficient funds |
700000003 |
times out |
There is also an amount-based lever: an amount between 1 and 100 returns a simulated 5xx from the gateway, which is how you exercise your retry path rather than your decline path. Anything else succeeds after a realistic delay of a few seconds, so you can see your pending state on screen instead of everything resolving instantly.
Test the timeout case properly. It is the one most integrations get wrong, because a timeout is genuinely ambiguous: the push may still have reached the customer. Treat it as unresolved and reconcile, rather than as a failure you can safely retry.
Answering opens shortly, with your Ultraner account. More in Integrations and the API
