Deliver Critical OTP & Transactional SMS Instantly

The primary difference lies in their purpose and regulations as defined by TRAI. Transactional SMS is used for sending essential, time-sensitive, and non-marketing information to your registered users. This includes OTPs, password resets, account balance alerts, and order confirmations. These messages can be sent 24/7 and can be delivered to numbers registered on the DND (Do Not Disturb) list. Promotional SMS, however, is used for marketing purposes like sending offers and discounts. These messages have time restrictions (9 AM to 9 PM) and cannot be sent to DND numbers. Choosing the right route is critical for compliance.

Yes, under the DLT regulations in India, all SMS content, including transactional messages, must be pre-approved. You need to create content templates that include fixed and variable parts. For example, an OTP template might be: “Your OTP for login is {#var#}. It is valid for 10 minutes.” The {#var#} part is where the unique OTP code is inserted. This process ensures that only legitimate and relevant information is being sent via the transactional route, preventing its misuse for promotional activities and enhancing the overall security of the messaging ecosystem for consumers.

For transactional messages, businesses can use a 6-character alphabetic Sender ID (also known as a Header) that represents their brand name, for example, ‘TMIMES’. This helps build immediate brand recognition and trust, as the customer instantly knows who the message is from. Unlike promotional messages which are restricted to numeric headers, this alphabetic ID signals to the recipient that the message contains important information. This Sender ID must be registered and approved on the DLT platform before it can be used to send any messages from our platform.

The Cascading Delivery system is an intelligent failover mechanism designed to maximize message reliability. When you send a critical message like an OTP, our platform first attempts to deliver it through a primary high-priority route. The system then waits for a delivery confirmation from the telecom operator. If this confirmation is not received within a predefined timeout period (usually a few seconds), the system automatically triggers and re-sends the message through a different, secondary high-priority route. This redundancy ensures that temporary network congestion or issues with one carrier do not prevent your critical message from reaching the user.

TTL, or Time-to-Live, is a parameter you can set for your messages that defines how long the system should keep trying to deliver it. This is especially important for time-sensitive messages like One-Time Passwords (OTPs). An OTP is typically only valid for a few minutes. Setting a short TTL (e.g., 2-3 minutes) ensures that if the message cannot be delivered almost instantly (for example, if the user’s phone is switched off), the system will stop trying. This prevents the user from receiving an old, expired OTP much later when they turn their phone back on, which avoids confusion and potential security risks.

Yes, we offer Voice OTP as a powerful backup solution. In scenarios where an SMS OTP might fail to deliver due to network issues or DND restrictions, your application can be configured to offer the user an alternative. If the user selects the voice option, our system will trigger an automated, secure voice call to their number. The call will then read out the OTP code to them. This provides a crucial fallback mechanism to ensure that users can always complete their verification process, significantly reducing login or transaction failures and improving the overall user experience on your platform.

Security is at the core of our platform, especially for our transactional SMS service. We are a SOC2-certified company, which means our systems and processes are regularly audited and meet stringent enterprise-grade standards for data security, availability, and confidentiality. All communication with our API is over secure, encrypted channels. We provide robust authentication mechanisms for your API access and adhere to all TRAI and data privacy regulations. When you partner with us as your OTP service provider, you can be confident that your sensitive user data is handled with the highest level of security.

Absolutely. We provide real-time, detailed delivery reports (DLRs) for every single message you send. Using our webhooks, your application can be instantly notified of the message status—whether it was delivered, failed, or expired. This allows you to track the performance of your SMS verification system programmatically and build logic into your application based on the delivery status. For example, if an OTP fails, you can automatically offer the user a resend option or the Voice OTP backup, creating a more intelligent and responsive system.

We are committed to providing a seamless experience for developers. Our transactional SMS API is built to be simple and easy to integrate. We provide comprehensive and clear API documentation with ready-to-use code samples in popular programming languages. In addition to our documentation, we have a dedicated technical support team available to assist you with any questions or challenges you might face during the integration process. Our goal is to help you get up and running as quickly as possible so you can focus on building your application’s core features.

Yes, the content for transactional messages is strictly regulated by TRAI to ensure it is purely informative and not promotional in nature. Your message templates must not contain any marketing language, offers, or discounts. They should be directly related to a transaction or interaction initiated by the user. For example, “Your order #12345 has been shipped” is a valid transactional message, whereas “Your order #12345 has been shipped. Get 20% off your next purchase!” would be considered promotional. All templates must be approved on the DLT platform before they can be used.