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.

Onboarding completes through browser redirect plus status polling; it does not publish server events.