Bulk SMS Services India — Transactional, Promotional & OTP SMS

Transactional SMS is triggered by a user action (e.g., placing an order, making a payment) and can be delivered 24/7, including to DND-registered numbers. It uses a 6-character alphabetic sender ID. Promotional SMS is used for marketing purposes and can only be delivered between 9 AM and 9 PM IST. It is filtered against the NDNC/DND registry and uses a numeric sender ID. Both require DLT-approved templates but have different delivery rules and audience restrictions.

DLT (Distributed Ledger Technology) is a blockchain-based compliance system mandated by TRAI for all commercial SMS in India. Every business must register as a Principal Entity on a DLT platform, approve sender IDs (headers), and register content templates before sending SMS. Without DLT registration, your messages will be blocked by all Indian telecom operators. SpringEdge simplifies this process — visit our DLT Registration Guide for complete instructions.

SpringEdge delivers OTP messages in under 3 seconds on average through direct carrier connectivity and intelligent failover routing. Transactional SMS are typically delivered within 5 seconds. Promotional SMS delivery depends on operator processing and the 9 AM – 9 PM delivery window. Our API response time is under 5 milliseconds, and the platform maintains 99.99% uptime with redundant infrastructure.

A Sender ID (also called a header) is the name or number that appears as the sender when recipients receive your SMS. For transactional SMS, it is a 6-character alphabetic code (e.g., SPREDG, HDFCBK). For promotional SMS, it is a numeric code assigned by the operator. Sender IDs must be registered and approved on your DLT platform before use. See our Sender ID Registration Guide for step-by-step instructions.

Yes. SpringEdge supports SMS delivery to 85+ countries through our international carrier network. International SMS does not require DLT registration (DLT applies only to Indian numbers). You can send OTPs, transactional alerts, and marketing messages to international numbers using the same API. Delivery speeds and routes are optimised per country for the best possible experience.

SpringEdge's SMS API is a standard RESTful API that works with any programming language capable of making HTTP requests. We provide ready-to-use code samples for cURL, PHP, Python, Java, Node.js, Go, Ruby, C#/.NET, and Android. The API accepts form-encoded or JSON requests and returns JSON or XML responses. Visit the Developers API page for complete documentation and code examples.

SpringEdge automatically filters promotional SMS against the NDNC (National Do Not Call) registry, also known as DND. Promotional messages are not delivered to DND-registered numbers — this is enforced by TRAI regulations. However, transactional SMS and OTP messages are exempt from DND filtering and can be delivered to all numbers at any time. The filtering happens automatically on our platform; no additional configuration is needed from your side.

SpringEdge's platform handles thousands of SMS requests per second without throttling. For bulk campaigns, our batch API processes millions of messages efficiently with automatic queuing and rate management. Throughput scales with your account configuration — enterprise customers with high-volume requirements can request dedicated sending capacity. Contact our sales team for custom throughput requirements.

Every SMS sent through SpringEdge returns a unique message ID. You can query the delivery status using our status API, or configure webhook callbacks to receive delivery reports (DLR) in real time. Delivery statuses include: submitted, delivered, failed, and rejected (with failure reason). The SpringEdge dashboard also provides real-time campaign analytics with delivery rates, failure analysis, and historical reports.

SpringEdge uses a pay-as-you-go pricing model with volume-based discounts. There are no monthly subscriptions, setup fees, or minimum commitments. Your per-SMS rate decreases as your purchase volume increases. Visit our pricing page for current rates and volume tiers, or contact our sales team for custom enterprise pricing on volumes above 10 lakh messages per month.

Yes. SpringEdge fully supports Unicode SMS, enabling you to send messages in Hindi, Tamil, Telugu, Marathi, Bengali, Gujarati, Kannada, and all other Indian languages, as well as international scripts like Arabic, Chinese, and Japanese. Unicode SMS has a 70-character limit per segment (compared to 160 for GSM-7 English). Your DLT templates must be registered in the same language and script as the messages you plan to send.

Create a free SpringEdge account to get started. You will receive test credits immediately to try the API. For Indian SMS, complete your DLT registration on any platform and share your Entity ID with us. We configure the PE-TM chain, and you can start sending live messages within 24 hours. For international SMS, no DLT is needed — you can start sending as soon as your account is set up.