OTP Authentication — SMS, Voice & WhatsApp OTP Delivery
Send and verify one-time passwords over SMS, voice or WhatsApp in seconds — securing every login, signup and transaction with DLT-compliant, high-priority delivery.
Overview
One-time passwords are the backbone of secure digital transactions, and speed matters — a delayed OTP means an abandoned signup or a failed payment. Office24by7 delivers OTPs over SMS, voice call and WhatsApp through high-priority transactional routes so codes arrive in seconds, with automatic fallback to a second channel if the first does not land. It secures user logins, registrations, password resets, payments and any action that needs verification.
The platform generates, sends and verifies codes end to end — you set the length, validity window and retry limits, and it handles expiry, resends and rate-limiting to block abuse. In India, transactional SMS runs on DLT-registered sender IDs and approved templates, and the system manages that compliance for you. Every OTP event is logged for audit, and delivery reporting shows exactly when each code was sent, delivered and verified.
Explore Omnichannel Communication →- ✓ OTP delivery over SMS, voice and WhatsApp
- ✓ High-priority transactional routes for seconds-fast delivery
- ✓ Automatic channel fallback if the first fails
- ✓ DLT-registered sender IDs and approved templates
- ✓ Configurable length, validity and retry limits
- ✓ Full audit log and delivery reporting
Everything OTP Authentication gives you
Multi-Channel OTP
Deliver one-time passwords over SMS, voice call or WhatsApp based on what suits each user.
Fast Delivery
High-priority transactional routes, with delivery status tracked for each OTP.
Channel Fallback
Automatically retry on a second channel, like voice, if the first delivery does not land.
Verify & Expire
Generate, verify and expire codes with configurable length, validity and resend limits.
DLT Compliance
Send transactional OTPs on DLT-registered sender IDs and approved templates as required in India.
Abuse Protection
Rate-limit requests and cap retries to block brute-force and OTP-flooding attempts.
How the agent works with OTP Authentication
The Flow-Cognition Agent runs a real loop on your OTP Authentication data — grounded in your records, governed and logged.
Sense
Watches OTP delivery and verification results per route and channel.
Decide
Spots failing routes and unusual request patterns.
Act
Switches to the fallback channel and flags suspected abuse for review, with every step logged.
Five-tier model routing · field-level permissions · full audit trail. See the AI layer →
Live in four steps
Trigger a Request
Your app requests an OTP for a login, signup or transaction via API.
Generate & Send
The platform creates a code and delivers it over SMS, voice or WhatsApp.
User Enters Code
The user submits the code, which is validated against the active window.
Verify & Log
The result is returned and every OTP event is logged for audit.
Where teams put it to work
Secure logins
A fintech app sends an SMS OTP at every login and step-up authentication for high-value transactions, with a voice-call fallback for users in low-network areas.
Signup verification
An e-commerce platform verifies each new mobile number with an OTP at registration, blocking fake accounts and confirming the contact is reachable.
Transaction approval
A service provider requires a one-time password to confirm sensitive changes like bank details or address, keeping an audit trail of every verification.
The payoff
Fewer drop-offs
Seconds-fast delivery and channel fallback mean users complete signups and payments instead of abandoning them.
Stronger security
Expiry windows, retry caps and rate-limiting protect accounts and transactions from abuse.
Compliant in India
DLT-registered sender IDs, approved templates and DPDP compliant handling with India-only data residency.
Complete audit trail
Every send, delivery and verification is logged, giving you proof and reporting for compliance.
Questions, answered
You can deliver one-time passwords over SMS, voice call and WhatsApp. Using more than one channel with automatic fallback improves delivery, so if an SMS does not land quickly a voice call can read the code instead.
Transactional OTP messages in India must use DLT-registered sender IDs and pre-approved templates. The platform manages sender IDs and templates so your OTP traffic stays compliant with the DLT framework.
Yes. You configure the code length, the validity window before it expires, and how many times a user can request or retry a code, giving you the balance of security and usability you need.
They are sent on high-priority transactional routes, and delivery status is tracked for every code.
The system rate-limits OTP requests per number, caps retries and expires codes quickly, which blocks brute-force guessing and prevents attackers from flooding a user with repeated OTP messages.
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Security & Policies
Roles, audit trails and policy controls that govern every action.
All of Communication
Explore every voice and messaging channel in one governed platform.
See OTP Authentication in your workflow
Start free, or get a guided walkthrough with our team — on the one platform that runs Omnichannel Communication and your whole business.