Callbacks

Onboarding, consent, payment approval, payroll approval, and some cancellation flows accept a callback or redirect URL for browser-based SCA. The bank or ZTL sends the user’s browser back to this URL.

A browser return:

• can be absent if the user closes the browser;
• can arrive before downstream processing settles;
• can be repeated or opened in another session; and
• is not proof of a successful resource outcome.

Preserve your own correlation state, validate it when the browser returns, and resume polling the relevant status endpoint.

For onboarding, the browser return does not confirm completion. Use GET /onboarding/{onboardingId}/status or subscribe to ONBOARDING_STATUS webhooks for public status changes. Fetch the status endpoint when you need signer details or to reconcile missed events.