Cheapest SMS API in India 2026 — Real Pricing, Real Code, Real Delivery
- TechTo Networks
- Aug 20, 2025
- 18 min read
If you are a developer or startup founder searching for the cheapest SMS API in India, you have almost certainly already discovered that "cheap" is the most abused word in this market. Every provider claims to be the cheapest. Fast2SMS claims ₹0.11/SMS. MSG91 quotes enterprise rates that are anything but budget-friendly. 2Factor charges per successful delivery. TextLocal's rates are competitive until you read the fine print. And a dozen comparison sites rank whoever pays for placement highest.
This page does something different. It gives you the actual numbers, the actual API code you need to integrate today, a fair comparison of what competitors offer, a plain-English explanation of TRAI DLT compliance costs (which dramatically affect your effective cost per SMS), and a clear explanation of where TechTo Networks sits in this market and why.
By the end of this page, you will have everything you need to make a fully informed decision on which SMS API provider in India offers you the best value for your specific use case — whether that is OTP verification, transactional alerts, or bulk promotional campaigns.
What Does "Cheapest SMS API in India" Actually Mean in 2026?
Before comparing prices, you need to understand what you are actually paying for when you use an SMS API in India. The per-SMS rate is only one component. The effective cost per delivered message — the number that actually matters — depends on four factors that most providers bury in their documentation.
Factor 1: Per-SMS Rate (The Headline Number)
This is the price per message charged from your credit balance. Providers quote this as low as ₹0.08–0.11 for bulk promotional routes to as high as ₹0.35 for single-message transactional sends. The rate you see advertised is almost always the best possible rate available only at maximum volume commitment.
Factor 2: Delivery Failure Rate (The Hidden Cost)
If a provider delivers only 85% of your messages successfully and does not refund credits for failures, your effective cost per delivered message is 18% higher than the quoted rate. A ₹0.12/SMS provider with 99% delivery is cheaper than a ₹0.10/SMS provider with 85% delivery. At 100,000 messages per month, the difference is ₹5,000 in wasted spend.
TechTo Networks refunds credits automatically for messages that fail before carrier submission (invalid numbers, DND filtering on promotional routes). For carrier-side failures on transactional routes, failed message credits are returned to your account within 24 hours.
Factor 3: DLT Setup and Support Costs
TRAI's DLT compliance mandate is not optional. Every commercial SMS sender in India must register their entity, sender IDs, and message templates before any message can be delivered. Many providers charge separately for this:
Sender ID registration: ₹200–500 per ID at some providers
Template submission assistance: ₹500–2,000 at others
Ongoing DLT support: Billed per support ticket at some platforms
At TechTo Networks, DLT registration support — entity setup, sender ID registration, and template batch submission — is included with every account, including the free tier. This alone saves ₹1,000–3,000 for a typical small business getting started.
Factor 4: Credit Expiry
Several providers expire your purchased credits after 6 or 12 months. If you buy 50,000 credits in January and only use 30,000 by June, 20,000 credits are lost at a provider with 6-month expiry. At ₹0.10/SMS, that is ₹2,000 gone without a single message sent.
TechTo Networks credits never expire. Buy once, use at your own pace.
What This Means for Effective Cost Comparison
Provider | Quoted Rate | Delivery Rate (Est.) | Credit Expiry | DLT Support | Effective Rate (Approx.) |
TechTo Networks | ₹0.08–0.10 | 99%+ | Never | Included | ₹0.08–0.10 |
Fast2SMS | ₹0.11–0.21 | 95–98% | 6 months | Self-serve | ₹0.12–0.22 |
MSG91 | ₹0.16–0.25 | 99%+ | 12 months | Included (higher tiers) | ₹0.17–0.26 |
2Factor | ₹0.20–0.35 | 99.5%+ | 12 months | Included | ₹0.20–0.35 |
TextLocal | ₹0.20–0.30 | 98%+ | 12 months | Self-serve | ₹0.21–0.31 |
SMSAlert | ₹0.12–0.18 | 97–99% | 12 months | Partial | ₹0.13–0.19 |
MessageCentral | Custom | 99%+ | Varies | Included | Custom |
Rates are estimates based on published pricing and market research as of May 2026. Verify directly with each provider before committing.
TechTo Networks SMS API Pricing — Full Transparency
Promotional SMS API (Marketing Campaigns, Offers, Broadcasts)
Pack | Credits | Price (incl. GST) | Per SMS | Valid |
Starter | 5,000 | ₹400 | ₹0.08 | Never expires |
Basic | 25,000 | ₹1,875 | ₹0.075 | Never expires |
Growth | 1,00,000 | ₹7,000 | ₹0.07 | Never expires |
Scale | 5,00,000 | ₹30,000 | ₹0.06 | Never expires |
Enterprise | 10,00,000+ | Custom | ₹0.055+ | Never expires |
Promotional SMS is delivered on DND-filtered routes, 9 AM – 9 PM, to non-DND numbers only.
Transactional SMS API (Alerts, Notifications, Account Messages)
Pack | Credits | Price (incl. GST) | Per SMS | Valid |
Starter | 5,000 | ₹500 | ₹0.10 | Never expires |
Basic | 25,000 | ₹2,250 | ₹0.09 | Never expires |
Growth | 1,00,000 | ₹8,000 | ₹0.08 | Never expires |
Scale | 5,00,000 | ₹35,000 | ₹0.07 | Never expires |
Enterprise | 10,00,000+ | Custom | ₹0.065+ | Never expires |
Transactional SMS is delivered on all-network routes, 24×7, including DND-registered numbers.
OTP SMS API (One-Time Passwords, Verification Codes)
Pack | Credits | Price (incl. GST) | Per OTP | Valid |
Starter | 5,000 | ₹600 | ₹0.12 | Never expires |
Basic | 25,000 | ₹2,625 | ₹0.105 | Never expires |
Growth | 1,00,000 | ₹9,000 | ₹0.09 | Never expires |
Scale | 5,00,000 | ₹37,500 | ₹0.075 | Never expires |
Enterprise | 10,00,000+ | Custom | ₹0.07+ | Never expires |
OTP SMS runs on a dedicated priority route isolated from all other traffic. Delivery target: under 1 second to Jio and Airtel under normal conditions.
Free Trial
Every new account receives 100 free SMS credits on signup — no credit card required. These work across all three routes so you can test OTP delivery, transactional alerts, and promotional sends before purchasing.
The TechTo Networks SMS API — Complete Technical Reference
Base URL and Authentication
Base URL: https://api.techtonetworks.com/v2
Authentication: Bearer token via Authorization header
Your API key is available immediately on signup under Settings → API Keys. Create separate keys per environment (sandbox, staging, production) and per service (OTP service, notification service, campaign service) for proper access control.
Endpoint 1: Send a Single SMS
POST https://api.techtonetworks.com/v2/sms/send
Content-Type: application/json
Authorization: Bearer YOUR_API_KEY
{
"to": "919876543210",
"message": "Your OTP for login is 492817. Valid for 10 minutes. - TechTo",
"sender_id": "TECHTO",
"route": "otp",
"template_id": "1007161234567890123"
}
Successful Response:
{
"status": "success",
"message_id": "msg_01HXZ4K9A7B2C4D",
"to": "919876543210",
"credits_used": 1,
"operator": "Jio",
"submitted_at": "2026-05-29T10:23:45.312Z",
"delivery_status": "submitted"
}
Error Response:
{
"status": "error",
"error_code": "TEMPLATE_MISMATCH",
"error_message": "Message content does not match DLT-registered template ID 1007161234567890123",
"request_id": "req_01HXZ4K8M2V3N9P"
}
Endpoint 2: Send Bulk SMS to Multiple Numbers
POST https://api.techtonetworks.com/v2/sms/bulk
Content-Type: application/json
Authorization: Bearer YOUR_API_KEY
{
"sender_id": "MYAPP",
"route": "transactional",
"template_id": "1007169876543210987",
"messages": [
{
"to": "919876543210",
"variables": {
"name": "Rahul",
"order_id": "ORD-1092",
"amount": "₹1,299"
}
},
{
"to": "919123456789",
"variables": {
"name": "Priya",
"order_id": "ORD-1093",
"amount": "₹899"
}
}
]
}
Supports up to 10,000 recipients per request. For volumes above 10,000, use the async batch endpoint at /v2/sms/batch with a callback_url parameter.
Endpoint 3: OTP Send and Verify
The OTP endpoint generates the OTP server-side and returns a signed session token. You verify against the token — no need to store raw OTP values in your database.
Send OTP:
POST https://api.techtonetworks.com/v2/otp/send
Content-Type: application/json
Authorization: Bearer YOUR_API_KEY
{
"to": "919876543210",
"otp_length": 6,
"expiry_seconds": 600,
"template_id": "1007175678901234567",
"app_name": "MyApp"
}
Response:
{
"status": "success",
"message_id": "msg_01HXZ7P2Q3R4S5T",
"otp_session_token": "sess_eyJhbGciOiJIUzI1NiJ9...",
"expires_at": "2026-05-29T10:33:45Z"
}
Verify OTP:
POST https://api.techtonetworks.com/v2/otp/verify
Content-Type: application/json
Authorization: Bearer YOUR_API_KEY
{
"otp_session_token": "sess_eyJhbGciOiJIUzI1NiJ9...",
"otp_entered": "492817"
}
{
"valid": true,
"verified_at": "2026-05-29T10:25:12Z"
}
Endpoint 4: Check Delivery Status
GET https://api.techtonetworks.com/v2/sms/status/msg_01HXZ4K9A7B2C4D
Authorization: Bearer YOUR_API_KEY
{
"message_id": "msg_01HXZ4K9A7B2C4D",
"status": "delivered",
"delivered_at": "2026-05-29T10:23:45.891Z",
"delivery_latency_ms": 579,
"operator": "Jio",
"credits_used": 1
}
Status values: submitted, dispatched, delivered, failed, dnd_filtered, invalid_number, template_rejected
Endpoint 5: Webhook Configuration
For production systems, configure a webhook to receive delivery receipts in real time rather than polling:
POST https://api.techtonetworks.com/v2/webhooks
Content-Type: application/json
Authorization: Bearer YOUR_API_KEY
{
"url": "https://yourapp.com/webhooks/sms",
"events": ["message.delivered", "message.failed"],
"secret": "your_signing_secret"
}
Delivery receipt payload pushed to your endpoint:
{
"event": "message.delivered",
"data": {
"message_id": "msg_01HXZ4K9A7B2C4D",
"to": "919876543210",
"status": "delivered",
"operator": "Airtel",
"delivered_at": "2026-05-29T10:23:45.891Z",
"delivery_latency_ms": 579
},
"signature": "sha256=a4b8c2d1e9f3..."
}
Always verify the HMAC-SHA256 signature before processing webhook events to ensure they originate from TechTo's infrastructure.
Quick Integration Code Samples
Node.js (Plain HTTP)
const axios = require('axios');
async function sendOTP(phoneNumber) {
const response = await axios.post(
'https://api.techtonetworks.com/v2/otp/send',
{
to: `91${phoneNumber}`,
otp_length: 6,
expiry_seconds: 600,
template_id: process.env.OTP_TEMPLATE_ID,
app_name: 'YourApp'
},
{
headers: {
'Authorization': `Bearer ${process.env.TECHTO_API_KEY}`,
'Content-Type': 'application/json'
}
}
);
return response.data.otp_session_token;
}
async function verifyOTP(sessionToken, userOTP) {
const response = await axios.post(
'https://api.techtonetworks.com/v2/otp/verify',
{ otp_session_token: sessionToken, otp_entered: userOTP },
{ headers: { 'Authorization': `Bearer ${process.env.TECHTO_API_KEY}` } }
);
return response.data.valid;
}
Python
import requests
import os
API_KEY = os.environ['TECHTO_API_KEY']
BASE_URL = 'https://api.techtonetworks.com/v2'
HEADERS = {'Authorization': f'Bearer {API_KEY}', 'Content-Type': 'application/json'}
def send_transactional_sms(phone: str, message: str, template_id: str, sender_id: str) -> str:
response = requests.post(
f'{BASE_URL}/sms/send',
json={
'to': f'91{phone}',
'message': message,
'sender_id': sender_id,
'route': 'transactional',
'template_id': template_id
},
headers=HEADERS
)
response.raise_for_status()
return response.json()['message_id']
def send_bulk_promotional(recipients: list, template_id: str, sender_id: str) -> str:
"""
recipients: [{'phone': '9876543210', 'variables': {'name': 'Rahul', ...}}, ...]
"""
messages = [
{'to': f"91{r['phone']}", 'variables': r['variables']}
for r in recipients
]
response = requests.post(
f'{BASE_URL}/sms/bulk',
json={
'sender_id': sender_id,
'route': 'promotional',
'template_id': template_id,
'messages': messages
},
headers=HEADERS
)
response.raise_for_status()
return response.json()['batch_id']
PHP
<?php
function sendSMS(string $phone, string $message, string $templateId, string $route = 'transactional'): array {
$apiKey = $_ENV['TECHTO_API_KEY'];
$ch = curl_init('https://api.techtonetworks.com/v2/sms/send');
curl_setopt_array($ch, [
CURLOPT_POST => true,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => [
"Authorization: Bearer $apiKey",
'Content-Type: application/json'
],
CURLOPT_POSTFIELDS => json_encode([
'to' => '91' . $phone,
'message' => $message,
'sender_id' => 'MYAPP',
'route' => $route,
'template_id' => $templateId
])
]);
$response = json_decode(curl_exec($ch), true);
curl_close($ch);
return $response;
}
cURL (Terminal testing)
curl -X POST https://api.techtonetworks.com/v2/sms/send \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"to": "919876543210",
"message": "Test message from TechTo API. - TECHTO",
"sender_id": "TECHTO",
"route": "transactional",
"template_id": "YOUR_TEMPLATE_ID"
}'
DLT Compliance — Why It Affects Your Cost and How TechTo Handles It
TRAI's Distributed Ledger Technology regulation is the single biggest hidden cost and operational complexity in Indian SMS API usage. Understanding it directly affects your cost-per-message calculation.
What DLT Registration Requires
Every commercial SMS sender in India must complete three registrations before any message is delivered:
1. Principal Entity Registration: Your company is registered on a TRAI-approved telecom operator's DLT platform. You submit your business name, GST number, PAN, and authorised signatory details. This is a one-time process.
2. Sender ID (Header) Registration: The 6-character name that appears as "From" in your customer's SMS inbox (example: "MYSHOP", "TECHTO", "BAKERS") must be pre-approved. Each sender ID takes 24–48 hours to activate and can be used across all DLT-compliant SMS providers.
3. Content Template Registration: Every category of message you send — promotional offer, order alert, OTP, appointment reminder, payment confirmation — must be registered as an approved template with variable placeholders. Templates must be approved before use and any message that does not match an approved template is blocked at the carrier level.
Why Many Businesses Get This Wrong
The most common and expensive mistake developers make is building their entire SMS integration, setting a launch date, and then discovering they need DLT templates approved 48 hours before go-live. Template approval during business hours on weekdays typically takes 24–36 hours. Submitted on a Friday evening? You're waiting until Monday.
A second common mistake is using incorrect route classification — sending marketing content on a transactional route (or vice versa). This is a TRAI violation that can result in your sender ID being suspended, blocking all your messages until the issue is resolved and an appeal is processed.
TechTo's DLT Support — What We Do For You
TechTo Networks treats DLT compliance as a platform service, not a billable extra:
Guided onboarding: When you create a TechTo account and begin the DLT setup, our compliance team walks you through every step. You provide your business information; we handle the submission on your behalf.
Template submission service: You describe in plain language what you want to send ("a message telling customers their order has shipped, including the order ID and a tracking link"). Our team formats it into a correctly structured DLT template and submits it with the right content category classification.
Approval tracking: We notify you when your entity registration, sender IDs, and templates are approved — with clear go/no-go status for each component. No manually checking multiple TRAI portal pages.
Proactive scrubbing alerts: TRAI's DLT system periodically runs "scrubbing" — re-validating all approved templates against updated criteria. Templates that previously passed can fail scrubbing silently, causing delivery failures on what was previously working. TechTo monitors scrubbing events and alerts you immediately with guidance on re-submission.
Ongoing compliance updates: When TRAI issues new circulars (which happens several times per year), TechTo's compliance team translates the regulatory language into plain-English action items for your account.
How TechTo Compares to the Top Competitors for "Cheapest SMS API India"
Here is an honest, detailed comparison based on public pricing, developer documentation, and feature sets as of May 2026. This is not a paid comparison — TechTo is listed with the same objectivity as every other provider.
Fast2SMS
Fast2SMS is India's most prominent budget SMS provider with 15+ years in the market and a strong developer community. It offers the lowest possible per-SMS rates at high volumes (₹0.11/SMS at ₹60,000+ top-up).
Where Fast2SMS wins: Absolute lowest per-SMS rate at very high volumes. Large developer community with abundant third-party tutorials. "Quick SMS" route allows sending without full DLT registration (a convenience for testing, though not DLT-compliant for commercial use).
Where TechTo wins over Fast2SMS: Credits on Fast2SMS expire in 6 months — TechTo credits never expire. Fast2SMS DLT support is entirely self-serve; TechTo handles submission for you. TechTo's API response structure is cleaner and more consistent. Sandbox environment on TechTo is more robust for testing. For OTP and transactional routes, TechTo's dedicated route architecture provides better latency isolation.
Verdict: Fast2SMS is the right choice if you send very high volumes (10 lakh+ per month) and handle all your own DLT compliance. TechTo is better if you want a cleaner developer experience, DLT support included, and no credit expiry.
MSG91
MSG91 is India's leading enterprise SMS and CPaaS platform — well-funded, developer-focused, and with an excellent feature set including multi-channel messaging, email, voice, and RCS alongside SMS.
Where MSG91 wins: Most mature multi-channel platform. Excellent documentation. Strong SDK library. Competitive enterprise pricing at scale. Feature-rich dashboard.
Where TechTo wins over MSG91: MSG91's pricing is significantly higher than TechTo at small to medium volumes — their transactional SMS starts around ₹0.16–0.25 versus TechTo's ₹0.08–0.10. MSG91 does not publicly list pricing for standard tiers, requiring a sales call for most accounts. TechTo's pricing is fully transparent without a sales conversation. For businesses that only need SMS (not the full CPaaS suite), TechTo is significantly more cost-effective.
Verdict: MSG91 is the right choice if you need a full omnichannel CPaaS platform (SMS + WhatsApp + email + voice + RCS) at enterprise scale. TechTo is better for businesses that primarily need SMS at the lowest total cost.
2Factor
2Factor is India's specialist OTP and phone verification provider. Its differentiating feature is SLA-based pricing: you are only charged if the OTP is delivered within a defined time window (typically 15 seconds). If delivery fails or is slow, you are automatically refunded.
Where 2Factor wins: The pay-per-successful-delivery model is genuinely useful for OTP-heavy applications. Strong reputation for OTP delivery speed. Sample code available for PHP, Python, Java, Android, iOS, and Ruby. WordPress/WooCommerce plugins.
Where TechTo wins over 2Factor: 2Factor's per-OTP pricing (₹0.20–0.35) is substantially higher than TechTo's OTP rate (₹0.075–0.12). The SLA pricing model, while innovative, means you pay a premium for the insurance. TechTo's bulk SMS and transactional SMS capabilities are broader — 2Factor is primarily an OTP specialist, so if you need both OTP and general messaging, you would pay 2Factor's premium rate for everything.
Verdict: 2Factor is worth considering if OTP reliability is your single biggest concern and you can absorb the premium cost. TechTo offers lower per-OTP rates with sub-second delivery on its dedicated OTP route.
TextLocal India
TextLocal is a UK-founded brand operating in India, known for its clean dashboard and easy campaign setup. Popular with marketing teams who prioritize ease of use over raw price.
Where TextLocal wins: Clean, intuitive interface that non-technical users appreciate. Good link tracking and campaign analytics. Established brand with a known reputation.
Where TechTo wins over TextLocal: TextLocal's pricing is among the highest in the Indian market (₹0.20–0.30/SMS), significantly above TechTo's rates. Their API is functional but not developer-first in design. DLT setup is self-serve. Credit packages are less flexible for lower-volume senders.
Verdict: TextLocal suits marketing teams at companies where the marketing department (not developers) manages SMS campaigns and price is secondary to ease. For developers or cost-conscious businesses, TechTo is considerably more affordable.
SMSAlert
SMSAlert is a mid-tier Indian provider with a solid reputation among SMBs, offering a balance of affordability and features including an easy-to-use panel and basic API.
Where SMSAlert wins: User-friendly panel. Competitive pricing in the ₹0.12–0.18 range. Good for businesses that need both a web panel and basic API access without heavy technical setup.
Where TechTo wins over SMSAlert: TechTo's per-SMS rates are lower at equivalent volumes. TechTo's API documentation is more comprehensive. TechTo's DLT support is more actively managed versus SMSAlert's self-serve model.
Understanding API Route Types — Which One Do You Need?
Choosing the wrong route is one of the most expensive mistakes in SMS API usage. It either wastes money (using an expensive transactional route for promotional messages) or violates TRAI regulations (using a promotional route for authentication messages). Here's the complete breakdown:
OTP Route
Use for: One-time passwords, login verification codes, transaction PINs, account verification links with a time-sensitive nature.
Characteristics: Dedicated infrastructure isolated from all promotional traffic. Highest delivery priority. Delivered to all numbers including DND-registered. Available 24×7. Sub-second delivery target. Highest per-message cost.
Required DLT category: OTP template registration.
When NOT to use it: For regular transactional notifications (order updates, payment confirmations) — this wastes your premium OTP credits. Only use for messages where delivery in under 2 seconds is genuinely critical.
Transactional Route
Use for: Order confirmations, shipment tracking updates, payment receipts, appointment reminders, account alerts, subscription renewal notices, any message triggered by a user action or business event that the customer needs.
Characteristics: Delivered to all numbers including DND-registered. Available 24×7. Delivery target under 3–5 seconds. Moderate per-message cost.
Required DLT category: Service Implicit or Service Explicit template registration.
When NOT to use it: For promotional/marketing messages — this would be a TRAI violation and risks sender ID suspension.
Promotional Route
Use for: Marketing offers, discount announcements, seasonal campaigns, product launches, newsletter-style communications.
Characteristics: Blocked on DND-registered numbers (a significant percentage of the Indian mobile base). Delivery window 9 AM – 9 PM only. Lowest per-message cost. Highest volume use case.
Required DLT category: Promotional template registration. Consent records required for the audience.
When NOT to use it: For any time-sensitive message (OTPs, alerts, time-bound notifications) or for messages that customers need regardless of their marketing preferences.
Service Explicit Route
Use for: Service messages that require explicit consent from the recipient, such as premium subscription notifications, financial product updates, or messages where the relationship between sender and recipient is explicitly commercial.
Characteristics: Similar delivery profile to transactional. Specific consent requirements under TCCCPR 2018. Separate DLT registration category.
SMS API Rate Limits and Throughput at TechTo Networks
Account Tier | API Requests/Min | Messages/Sec (Burst) | Max Batch Size | Webhooks |
Free (100 credits) | 10 | 10 | 100 | 1 endpoint |
Starter | 60 | 100 | 1,000 | 3 endpoints |
Growth | 300 | 1,000 | 10,000 | 10 endpoints |
Scale | 1,000 | 5,000 | 10,000 | Unlimited |
Enterprise | Custom | Up to 50,000 | 10,000 + async | Unlimited |
Rate limit headers are returned on every response:
X-RateLimit-Limit: 300
X-RateLimit-Remaining: 247
X-RateLimit-Reset: 1748521500
Retry-After: 12
When you hit a rate limit, implement exponential backoff with jitter. Never retry on a fixed interval — this creates synchronized retry storms across accounts and degrades the platform for everyone.
Error Codes Reference
Error Code | HTTP Status | Meaning | Action |
INVALID_API_KEY | 401 | Key missing, expired, or revoked | Regenerate key in dashboard |
INSUFFICIENT_CREDITS | 402 | Balance too low | Top up or enable auto-recharge |
INVALID_NUMBER | 422 | Invalid format or unreachable | Validate before calling API |
TEMPLATE_MISMATCH | 422 | Content doesn't match DLT template | Fix message content |
TEMPLATE_NOT_APPROVED | 422 | Template pending or rejected | Check DLT status in dashboard |
SENDER_NOT_REGISTERED | 422 | Sender ID not DLT-approved | Register sender ID (24–48hr) |
ROUTE_VIOLATION | 422 | Wrong route for content category | Check route parameter |
DND_BLOCKED | 200* | Number is DND, promotional blocked | Use transactional route |
RATE_LIMIT_EXCEEDED | 429 | Too many requests | Backoff and retry |
CARRIER_REJECTION | 503 | Temporary carrier-side issue | Retry with backoff |
INTERNAL_ERROR | 500 | Platform error | Retry once; contact support if persistent |
*DND_BLOCKED returns HTTP 200 because the API call succeeded — the message was processed, it was just filtered by the DND registry. Credits are not charged for DND-blocked messages.
Sandbox Environment — Test Without Spending Credits
Every TechTo account includes a full sandbox environment where you can build and test your integration without sending real SMS or consuming real credits.
Sandbox base URL: https://sandbox.api.techtonetworks.com/v2
The sandbox mimics production API responses exactly, including error responses. You can simulate specific delivery outcomes:
{
"to": "919876543210",
"message": "Test OTP: 123456",
"route": "otp",
"template_id": "sandbox_any",
"sandbox_simulate_status": "delivered",
"sandbox_simulate_latency_ms": 750
}
Simulate failures by setting sandbox_simulate_status to failed, dnd_filtered, or template_rejected. This lets you test your error handling code paths thoroughly before going live.
DLT template validation is skipped in sandbox mode — use any string as template_id. When you switch to production, replace with real approved template IDs.
Frequently Asked Questions — Cheapest SMS API India
Q: Is TechTo Networks really the cheapest SMS API in India or is this just marketing?
Honest answer: it depends on your volume and use case. For low-to-medium volumes (under 5 lakh messages per month) across promotional, transactional, and OTP routes, TechTo's pricing is among the lowest in India when you factor in DLT support (included), no credit expiry, and effective delivery rates. For very high-volume promotional SMS (10 lakh+ per month), Fast2SMS's top-tier rate of ₹0.11 becomes competitive. We recommend comparing on effective cost per delivered message, not quoted rate per SMS.
Q: How does TechTo's OTP delivery speed compare to 2Factor and MSG91?
TechTo's dedicated OTP route delivers under 1 second to Jio and Airtel under normal network conditions, and under 2 seconds to Vi and BSNL. 2Factor's average delivery time is quoted at 2–6 seconds. MSG91's OTP route typically delivers in 1–3 seconds. For most OTP use cases (login verification with a 60-second or longer timeout), all three are fast enough. For payment authentication where a 30-second timeout is enforced, TechTo's sub-second delivery provides a meaningful margin.
Q: Can I use TechTo's SMS API without DLT registration for testing?
Yes. In sandbox mode, DLT registration is not required. You can develop and test your complete integration in sandbox before submitting DLT applications. For production sends to real Indian mobile numbers, DLT registration is mandatory — there is no legal path around this for commercial SMS in India.
Q: What happens if my DLT template is rejected?
TechTo notifies you immediately with the TRAI-stated rejection reason. Most rejections fall into three categories: (1) content category mismatch — the template content doesn't match the category it was filed under, (2) restricted content — certain financial, healthcare, or government-related claims require additional documentation, (3) formatting issues — variable placeholders not correctly structured. Our compliance team helps you resubmit with the correct formatting in most cases.
Q: Does TechTo support sending SMS in Kannada, Hindi, Tamil, Telugu, and other Indian languages?
Yes. Unicode SMS is supported across all routes. Set "unicode": true in your API request. Note that Unicode messages use 70 characters per credit (versus 160 for ASCII). A 130-character Hindi message costs 2 credits, not 1. Factor this into your cost calculations for vernacular campaigns.
Q: What is the maximum message length?
160 characters for a standard ASCII single-part SMS (1 credit). 306 characters for a 2-part concatenated SMS (2 credits). 459 characters for 3-part (3 credits). For Unicode (Indian languages): 70 characters per credit, 134 characters for 2-part. We recommend keeping messages under 160 characters whenever possible — it reduces cost and improves readability.
Q: Is there a setup fee, monthly fee, or any recurring charge?
No setup fee. No monthly fee. No account maintenance charge. No minimum monthly spend. Pay only for the SMS credits you purchase. Credits never expire. This applies to all account tiers including free.
Q: Can I get a reseller account to offer SMS services to my clients under my own brand?
Yes. TechTo offers a white-label reseller programme with a custom-branded panel, separate client accounts, custom pricing per client, and consolidated billing. Contact our partnerships team for reseller pricing and setup details.
Q: How do I migrate from my current SMS API provider to TechTo?
Migration typically involves three steps: (1) Create a TechTo account and complete DLT registration — importantly, your DLT registrations (sender IDs, templates) are registered to your company, not your current provider, so they are fully portable to TechTo without re-approval. (2) Update your API integration — swap the base URL, API key, and adjust request parameters to match TechTo's API format. Our migration documentation covers the mapping from MSG91, Fast2SMS, TextLocal, 2Factor, and Kaleyra formats. (3) Run parallel for 1–2 weeks — keep your old provider active while validating TechTo delivery on live traffic before full cutover.
Q: Does TechTo support WhatsApp Business API alongside SMS?
Yes. TechTo Networks provides WhatsApp Business API as a separate product alongside its SMS platform. Both are accessible from the same account dashboard and billing interface. If you need to build an omnichannel notification flow (primary: WhatsApp, fallback: SMS), TechTo supports this from a single API integration point.
Who Should Use TechTo Networks' SMS API
TechTo Networks is the best-fit SMS API for the following profiles:
Early-stage startups and indie developers: Low entry cost (₹400 for 5,000 messages), no credit expiry, a sandbox environment that works without DLT approvals, and DLT setup support included — all reducing the overhead of getting SMS working for your MVP.
Mid-size businesses with monthly volumes between 25,000 and 5,00,000 messages: This is the sweet spot where TechTo's pricing is most competitive against MSG91, TextLocal, and SMSAlert — which all price significantly higher at these volumes.
E-commerce and D2C brands needing both OTP and transactional SMS: Having OTP, transactional, and promotional routes on one platform with unified billing and a single API key simplifies operations compared to using multiple providers.
Developers who want a clean API without sales calls: TechTo's pricing is published, accounts activate instantly, and free trials don't require credit card or sales qualification. You can test before talking to anyone.
Businesses migrating from a current provider due to cost or DLT compliance issues: TechTo's migration support and DLT portability make switching straightforward.
Getting Started Today
Creating a TechTo Networks account takes under 3 minutes. No credit card required for the free trial. Your 100 free SMS credits are loaded immediately and work across all routes in sandbox mode.
For production use, the fastest path to live SMS is:
Sign up and get your API key — immediate, no approval wait
Integrate in sandbox — build and test your SMS flow using any template ID
Submit DLT registration — provide your business name, GST, PAN, and preferred sender ID. TechTo handles the submission. Approval typically takes 24–48 hours on weekdays.
Submit message templates — describe what you want to send; TechTo formats and submits them
Go live — switch from sandbox to production base URL, add your real template IDs, and start sending
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Final Word: What "Cheapest" Really Means for Your Business
The cheapest SMS API in India is not the one with the lowest headline rate. It is the one where your effective cost per delivered message — after accounting for delivery failure rates, DLT support costs, credit expiry, support quality, and integration time — is lowest for your specific use case and volume.
For most developers and businesses in India operating at low to medium SMS volumes, TechTo Networks delivers the best combination of competitive per-SMS pricing, zero hidden fees, included DLT support, and a developer-first API that gets you to production fast.
For very high-volume promotional SMS senders above 10 lakh messages per month, Fast2SMS's top-tier rate may be marginally lower — though you will handle all DLT compliance independently and manage credit expiry carefully.
For OTP-critical applications where you need pay-per-successful-delivery insurance, 2Factor's model is worth the premium — though TechTo's dedicated OTP route provides sub-second delivery at a fraction of 2Factor's per-OTP cost.
Make the decision based on your actual numbers, not marketing claims — including ours.
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