Why OTP Messages Should Have an Expiry Time

The security of your OTP delivery system directly impacts your users' trust in your platform. A fast, reliable OTP delivery mechanism is not just a technical requirement — it is a business necessity.

How OTP Verification Works

When a user initiates a sensitive action — login, transaction, password reset — the system generates a random one-time code and sends it to the user's registered phone number or email. The user enters this code to verify their identity, adding a crucial second factor of authentication.

Choosing the Right OTP Channel

SMS is the most common OTP delivery channel, but WhatsApp and voice calls offer alternatives. SMS has universal reach, WhatsApp provides read receipts, and voice works for users who cannot receive text messages. Connect Pulse supports all three channels for OTP delivery.

Preventing OTP Abuse

Rate limiting OTP requests prevents abuse — both from attackers trying to brute-force codes and from bots generating unnecessary costs. Implement per-number rate limits and CAPTCHA verification for repeated requests.

Multi-Channel Fallback

If SMS delivery fails, having a fallback to WhatsApp or voice OTP ensures your users can still complete verification. This multi-channel approach improves the overall success rate of your authentication system.

TOTP vs SMS OTP: Understanding the Difference

Time-based One-Time Passwords (TOTP) generated by apps like Google Authenticator differ fundamentally from SMS OTPs. TOTP works offline and is immune to SIM-swapping attacks, but requires users to install an authenticator app. SMS OTP is universally accessible — every phone can receive SMS — making it the practical choice for markets like Pakistan where smartphone-only solutions exclude a significant portion of the audience.

Take Your Campaigns to the Next Level

Whether you are just getting started or looking to optimize existing campaigns, having the right tools makes all the difference. Sign up for Connect Pulse today and experience the simplicity of managing SMS, WhatsApp, Voice, and Email campaigns from a single, powerful dashboard.