OTP Delivery Status: Polling APIs vs Webhooks in Production

Our deliverability checklist focuses on templates, numbers, and carriers. This post covers a separate topic: how your backend learns whether an OTP SMS was delivered and how to act on that signal—without re-explaining DLT or sender IDs.

Different From Deliverability Guides

Deliverability asks "will the message arrive?" Status tracking asks "did it arrive yet, and what state is it in?" You need both for support tooling and for smart resend UX.

Polling the Messages API

After you call send OTP, you receive an identifier. Polling means calling a status endpoint on a schedule until the terminal state (delivered, failed, expired) appears. Advantages: simple mental model, works behind strict firewalls. Disadvantages: latency to learn failure, wasted requests if you poll too often.

Combine polling with idempotency keys so a background job that rechecks status never accidentally triggers a second billable send.

Webhooks and Event-Driven Flows

Webhooks push status changes to your HTTPS endpoint. They reduce poll traffic and speed up analytics when your provider supports them. Costs: you must verify signatures, handle retries, and keep endpoints highly available. Many teams use a queue: webhook handler enqueues an event, workers update user-visible state.

Linking Status to User Experience

When status is failed, your UI should offer resend—not silent failure. When status is delayed, show honest timing copy. Align with the state machine described in our OTP verification flow guide. If you switch providers, replay the same patterns using migration practices.

FAQ

See above.