How to Send Bulk SMS Messages — Step-by-Step Guide for Beginners
- TechTo Networks
- Jul 5, 2025
- 24 min read
Updated: May 13
If you have never sent a bulk SMS campaign before, the process can look complicated from the outside — contact lists, DLT registration, sender IDs, template approvals, character limits. This guide removes all of that confusion.
By the time you finish reading, you will know exactly how to send bulk SMS messages in India using TechTo Networks' platform — from creating your account to reading your delivery report. Every step is explained in plain language, with real examples, common mistakes called out before you make them, and screenshots of what you will see on the TechTo dashboard.
This guide is written for first-time users. No technical background required.
What Is Bulk SMS and Why Does It Work?
Bulk SMS is the process of sending a single text message — or a set of personalised messages — to a large number of recipients simultaneously, using an online platform or API. Instead of typing and sending individual texts from your phone, you upload a list of contacts, compose your message once, and the platform delivers it to every number on your list within seconds.
Why it works better than almost every other marketing channel:
98% open rate — nearly every SMS is read, versus 20–30% for email.
90% read within 3 minutes — no other channel gets messages in front of customers this fast.
No algorithm gatekeeping — unlike social media or email, SMS does not get filtered by an algorithm that decides whether your message is worth showing.
Reaches every phone — not just smartphones. Feature phones receive SMS too, making it the broadest-reach channel in India.
Costs ₹0.10–0.22 per message — one of the lowest cost-per-reach channels available.
But bulk SMS in India has one layer that most international guides skip entirely: TRAI's DLT compliance framework. Before you can send a single commercial SMS to an Indian mobile number, you must register your business, your sender ID, and your message content on the DLT (Distributed Ledger Technology) portal. We cover this in full detail in Step 3.
Before You Start — Prerequisites Checklist
Before logging into TechTo and creating your first campaign, confirm you have the following ready:
[ ] Business documents — PAN card, GST certificate, Certificate of Incorporation or business registration (needed for DLT registration)
[ ] Contact list — Phone numbers of the customers you want to message, in a spreadsheet
[ ] Message content — A draft of what you want to say (we will help you refine it)
[ ] Sender ID — The name or number you want recipients to see as the sender (e.g., TECHTO, MYSHOP)
[ ] Campaign objective — Know whether this is a promotional message (offer, sale, discount) or a transactional message (order confirmation, OTP, appointment reminder) — the rules differ
If you have all five, you are ready to begin.
Step 1 — Create Your TechTo Networks Account
Time required: 2 minutes
Go to techtonetworks.com/register and create your free account. You will need:
A valid business email address
Your mobile number (for OTP verification)
Your business name
On successful registration, TechTo automatically generates:
Your API Key (under Dashboard → Developer → API Keys)
A sandbox environment for testing
100 free SMS credits — no credit card required
What you will see on your first login:
The TechTo dashboard has five primary sections in the left navigation panel:
Section | What It Does |
Campaigns | Create, schedule, and manage all bulk SMS campaigns |
Contacts | Upload and manage your contact lists and segments |
Templates | Store your DLT-registered message templates |
Reports | View delivery reports, click tracking, and campaign analytics |
Settings | Manage sender IDs, API keys, credits, and account details |
Your first step after logging in is to complete your DLT registration — without which no commercial messages will be delivered to Indian numbers.
Step 2 — Understand the Two Types of Bulk SMS Before You Set Anything Up
This is the step most beginners skip — and it causes delivery failures, compliance violations, and wasted credits.
In India, every commercial SMS belongs to one of two categories. The category determines your sender ID format, the routing your message travels, whether it can reach DND-registered numbers, and what time of day it can be sent. Getting this wrong means your messages either never arrive or result in TRAI complaints.
Promotional SMS
A promotional SMS is any message you send to promote a product, service, sale, event, or offer.
Rules for promotional SMS:
Can only be sent between 9:00 AM and 9:00 PM — messages dispatched outside this window are blocked by carriers.
Cannot reach DND-registered numbers — TRAI's Do Not Disturb registry blocks promotional messages from these numbers automatically.
Sender ID is a 6-digit numeric code (e.g., 567890) — not a brand name.
DLT template registration required.
Example promotional message:
"SALE ALERT! 40% off all orders today. Use code SAVE40. Shop: bit.ly/mystore. -567890"
Transactional SMS
A transactional SMS is any message that delivers essential service information — an OTP, order confirmation, appointment reminder, payment receipt, or account alert — related to a service the recipient is already using.
Rules for transactional SMS:
Can be sent 24 hours a day, 7 days a week — no time restrictions.
Reaches all numbers including DND — because the message is service-related, not promotional.
Sender ID is a 6-character alphanumeric brand name (e.g., TECHTO, MYBANK) — recognisable to the recipient.
DLT template registration required.
Example transactional message:
"Your order #ORD1234 has been shipped. Track: bit.ly/trk1234. Expected: 05-Jul. -MYSHOP"
How to decide which type you need:
Ask yourself: "Is this message promoting something, or confirming/informing about something the customer already did or has?" If promotion → Promotional. If confirmation or service alert → Transactional.
Step 3 — Complete Your DLT Registration (India-Specific)
Time required: 2–5 business days (one-time setup)
This is the most important step in the entire guide — and the one that is completely absent from every international "how to send bulk SMS" tutorial. In India, TRAI's DLT mandate requires every business sending commercial SMS to register before sending a single message. Skip this and your messages will be blocked at the carrier level.
TechTo Networks guides you through DLT registration as part of onboarding. Here is what the process involves:
3a — Register Your Business Entity (PE Registration)
Go to one of the six DLT portal options (TechTo recommends Jio or Airtel for fastest approvals):
Jio DLT: trueconnect.jio.com
Airtel: dltconnect.airtel.in
Vi (Vodafone Idea): vilpower.in
BSNL: smsdlt.bsnl.co.in
Tata: tatateleservices.com/dlt
Tanla/Wisely: wisely.tatatele.in
Documents you will need to upload:
PAN card of the business (or proprietor for sole proprietorships)
GST registration certificate
Certificate of Incorporation (Pvt Ltd/LLP) or Shop Act Licence (for proprietorships)
Aadhaar-linked mobile number of the authorised signatory
After submitting, your registration is reviewed by the telecom operator. Approval typically arrives within 2 to 5 business days. You will receive your Principal Entity (PE) ID — a unique identifier for your business on the DLT network.
Inside TechTo dashboard: Go to Settings → DLT Registration and enter your PE ID once approved. TechTo links it to your account automatically.
3b — Register Your Sender ID (Header)
Your Sender ID is what recipients see as the "from" name when they receive your message.
For promotional SMS: A 6-digit numeric header (e.g., 567890). Log into your DLT portal → Header Registration → Promotional → Submit. The portal assigns a numeric code.
For transactional SMS: A 6-character alphanumeric header of your choice (e.g., TECHTO, MYSHOP, CLINIC). Log into your DLT portal → Header Registration → Service Implicit or Service Explicit → Enter your preferred name → Submit.
Approval takes 24 to 72 hours per header.
Tips for choosing a good Sender ID:
Use a name your customers will recognise instantly — not a random abbreviation.
Keep it brand-consistent. If your brand is "MyStore," register MYSTOR or MSTORE (6 chars max).
You can register multiple sender IDs (one for marketing, one for OTPs, one for service alerts).
Inside TechTo dashboard: Go to Settings → Sender IDs → Add Sender ID and enter the header exactly as registered on your DLT portal.
3c — Register Your Message Templates
Every unique message structure you send must be registered as a template. This is the step most beginners find confusing — so let us walk through it carefully.
A template is the fixed structure of your message, with variable content (customer names, order IDs, OTPs, offer codes) marked as {#var#} placeholders.
Example: Turning a real message into a DLT template
Your real message:
"Hi Rahul, your order #ORD1234 is confirmed. Delivery by 05-Jul. Track: bit.ly/trk1234. -MYSHOP"
The DLT template you register:
"Hi {#var#}, your order #{#var#} is confirmed. Delivery by {#var#}. Track: {#var#}. -MYSHOP"
Rules for template registration:
Every dynamic field — name, order number, date, link, OTP — must be replaced with {#var#}.
The fixed parts of the message (the words that never change) must be written exactly as they will appear. A comma in the wrong place, or a capital letter difference, counts as a mismatch and causes the message to be blocked.
Register the template under the correct category: Promotional, Service Implicit, or Service Explicit.
One template per unique message structure. If you have 10 different campaign messages, you need 10 registered templates.
How to register a template on the DLT portal:
Log into your DLT portal.
Go to Content Templates → Add Template.
Enter the template name (your internal reference — not visible to recipients).
Select the category: Promotional / Service Implicit / Service Explicit.
Select the header (Sender ID) this template will be used with.
Paste the template content with {#var#} placeholders in place of all variable fields.
Submit.
Template approval typically takes 24 to 72 hours.
Inside TechTo dashboard: Go to Templates → Add Template and enter the Template ID shown on your DLT portal after approval. TechTo stores all your approved templates here, making them selectable when composing campaigns.
TechTo DLT compliance shortcut: TechTo's compliance team will handle your entire DLT registration — PE ID, Sender IDs, and templates — on your behalf. Contact support after account creation to request assisted DLT onboarding.
Step 4 — Prepare Your Contact List
Time required: 15–30 minutes (first time)
Your contact list is the audience for your bulk SMS campaign. TechTo accepts contact lists in CSV (Comma-Separated Values) format — a spreadsheet saved as a .csv file.
Required CSV Format
Your CSV file must have at least one column: the mobile number. Additional columns allow personalisation.
Minimum required CSV (numbers only):
mobile
9876543210
8765432109
7654321098
Recommended CSV with personalisation fields:
mobile,first_name,last_name,city,last_purchase_amount,offer_code
9876543210,Rahul,Sharma,Mumbai,4999,DIWALI20
8765432109,Priya,Nair,Chennai,2350,DIWALI20
7654321098,Arjun,Singh,Delhi,7800,DIWALI25
The column header names can be anything — TechTo lets you map them to personalisation tokens when uploading. But keep them consistent across all your files.
Mobile Number Formatting Rules
TechTo accepts Indian mobile numbers in any of these formats and normalises them automatically:
You Enter | TechTo Normalises To |
9876543210 | +919876543210 |
09876543210 | +919876543210 |
+919876543210 | +919876543210 |
919876543210 | +919876543210 |
What not to include in your CSV:
Landline numbers (8-digit, or starting with 0XX area codes) — SMS cannot be delivered to landlines.
Numbers with spaces or dashes (9876 543 210 or 987-654-3210) — clean these before uploading.
Numbers outside India without country code — if sending internationally, always include the +[country code] prefix.
Duplicate numbers — TechTo automatically de-duplicates, but cleaning your file first saves processing time.
Cleaning Your Contact List
A dirty list wastes your credits, inflates your delivery failure rate, and can trigger DND complaints. Before uploading:
Remove duplicates — In Excel: Data → Remove Duplicates → select the mobile column.
Check number length — Indian mobile numbers are exactly 10 digits. Filter for numbers with fewer or more digits and remove them.
Remove opted-out contacts — Anyone who has previously asked to stop receiving SMS from you must not be included.
Verify the DND status for promotional campaigns — TechTo automatically filters DND numbers for promotional campaigns at send time. However, knowing your approximate non-DND reach in advance helps with budget planning.
Collecting Contacts Legitimately
For promotional SMS, you can only message customers who have explicitly or implicitly opted in. Legitimate collection methods include:
Website opt-in form — "Enter your mobile number to receive exclusive offers." TechTo provides embeddable opt-in forms.
Checkout page — "Tick to receive order updates and exclusive offers via SMS" during the checkout process.
Keyword opt-in — Advertise "Text OFFER to 9999XXXXXX for 20% off" on your packaging, receipts, or social media.
QR code at physical location — Customers scan the QR code which opens a pre-filled opt-in form.
In-person sign-up — Trade show, store visit, or event registration with SMS opt-in checkbox.
Never purchase contact lists. Purchased lists contain unknown numbers, invalid numbers, and DND-registered numbers. They generate high complaint rates, TRAI violations, and carrier-level blacklisting of your sender ID.
Step 5 — Upload Your Contact List to TechTo
Time required: 2–5 minutes
From the TechTo dashboard, click Contacts in the left navigation.
Click + New List and give your list a descriptive name (e.g., "Mumbai Customers - July 2025" or "All Active Buyers - Diwali Campaign").
Click Upload CSV and select your prepared .csv file.
TechTo shows you a preview of the first 5 rows and asks you to map columns:
Which column contains the mobile number? → Select from dropdown.
Which column is first name? → Select if present.
Any other custom fields? → Map them here.
Click Import. TechTo processes the file, de-duplicates, validates number formats, and shows you the final import summary:
Total records in file: 5,240
Valid mobile numbers imported: 5,118
Duplicates removed: 62
Invalid numbers skipped: 60
Your contacts are now stored in TechTo and ready to use in campaigns.
Creating segments from an uploaded list: After uploading, go to the contact list and click Create Segment. Add filter conditions — for example, City = "Mumbai" AND Last Purchase Amount > 2000. Save the segment with a name. This segment is now available as a target audience when building campaigns.
Step 6 — Add Credits to Your Account
Time required: 2 minutes
TechTo operates on a pre-paid credit system. You purchase SMS credits upfront, and credits are deducted per message sent.
Go to Settings → Credits → Add Credits. Choose a credit pack or enter a custom amount. Payment via UPI, Net Banking, or card.
Pricing reference (as of 2025):
Route | Price per SMS |
Promotional | ₹0.10 – ₹0.18 depending on volume |
Transactional | ₹0.15 – ₹0.22 depending on volume |
OTP (Express) | ₹0.18 – ₹0.28 |
How many credits do you need? Estimate: Number of contacts in your campaign × average segments per message.
A 160-character English message = 1 segment. A 200-character message = 2 segments (second segment billed separately). A Hindi message of 70 characters = 1 Unicode segment. A Hindi message of 140 characters = 2 Unicode segments.
Example: 10,000 contacts × 1-segment promotional message × ₹0.15/SMS = ₹1,500 total campaign cost.
The 100 free credits awarded on signup are sufficient for your first test campaign.
Step 7 — Create Your First Bulk SMS Campaign
Time required: 10–15 minutes
From the dashboard, click Campaigns → + New Campaign.
Enter a Campaign Name — this is internal only, not visible to recipients. Use something descriptive: "Diwali Sale Blast - Oct 2025" or "Appointment Reminders - Week 28."
Select the Campaign Type:
Promotional — for marketing messages (sale, offer, announcement)
Transactional — for service messages (order, appointment, alert)
OTP — for one-time password delivery
Step 8 — Craft Your Bulk SMS Message
Time required: 5–10 minutes
This is where most beginners either get blocked (DLT mismatch) or get poor results (weak copy). Let us cover both.
Selecting a DLT Template
In the campaign composer, click Select Template and choose from your registered and approved DLT templates. The template populates the message field with the fixed content and {#var#} placeholders.
You then fill in the variable mapping — telling TechTo which column in your contact list corresponds to each {#var#} in the template:
Template Placeholder | Maps to CSV Column |
First {#var#} (customer name) | first_name |
Second {#var#} (offer code) | offer_code |
Third {#var#} (expiry date) | Fixed value: "31-Oct" |
The result: every recipient gets a personalised message with their own name and offer code, automatically generated from your contact list.
Writing Effective Bulk SMS Copy
If you are creating a new template for registration, here is how to write copy that converts:
The 4-part formula for high-CTR SMS:
Personalisation — Start with the recipient's name where possible. "Hi Rahul" beats "Dear Customer" every time. Personalised messages average 22–31% higher CTR.
Specific value proposition — State exactly what you are offering. "40% off" beats "great discount." "₹200 off your next order" beats "special offer."
Urgency or scarcity — Give a real reason to act now. "Today only," "Ends midnight," "First 100 customers," "Only 8 seats left." Vague urgency ("Limited time!") does not work. Specific urgency does.
One clear CTA — One link, one action. "Shop now: [link]" or "Book here: [link]" or "Call 9999XXXXXX." Never give two options — it dilutes action.
Message length and character rules:
Language | Encoding | 1 Segment | 2 Segments | 3 Segments |
English | GSM-7 | Up to 160 chars | 161–306 chars | 307–459 chars |
Hindi/Tamil/other | Unicode | Up to 70 chars | 71–134 chars | 135–201 chars |
Mixed (emoji) | Unicode | Up to 70 chars | Same as Unicode | Same as Unicode |
The TechTo campaign composer shows a live character counter, segment count, encoding indicator (GSM-7 or Unicode), and an estimated cost for the full campaign as you type. Watch these in real time before you schedule.
Characters to avoid to stay in GSM-7 encoding:
Curly/smart quotes: " " — replace with straight quotes "
Em-dashes: — — replace with hyphens -
Ellipsis character: … — replace with three full stops ...
Any emoji — all emojis force Unicode encoding
Any regional language character — switches to Unicode
Real message examples that work:
Retail promotional (GSM-7, 132 chars):
"Hi {name}, FLASH SALE! 35% off all orders above ₹999. Code: SAVE35. Today only. Shop: bit.ly/sale35. Reply STOP to opt-out. -567890"
E-commerce transactional (GSM-7, 128 chars):
"Hi {name}, your order #{order_id} has been shipped! Track live: {link}. Expected: {date}. -MYSHOP"
Healthcare appointment reminder (GSM-7, 141 chars):
"Reminder: Your appointment with Dr. {doctor} is on {date} at {time}. {clinic_name}, {address}. Reply CANCEL to reschedule. -CLINIC"
EdTech fee reminder (GSM-7, 135 chars):
"Hi {name}, {student_name}'s fee of ₹{amount} is due on {date}. Pay now: {link}. Questions? Call {phone}. -SCHOOL"
Banking OTP (GSM-7, 98 chars):
"Your OTP for {action} is {otp}. Valid for {minutes} minutes. Do not share. -MYBNK"
Previewing Your Message
Before proceeding, click Preview in the campaign composer. TechTo shows:
The message as it will appear on an Android phone
The message as it will appear on an iPhone
A sample with the first contact's variables filled in (so you can verify personalisation is working)
The character count, segment count, and encoding
Check the preview carefully. Look for:
{#var#} placeholders that did not get filled — this means a column mapping was missed
Unexpected characters that switched encoding from GSM-7 to Unicode
Message cut-off due to a segment boundary mid-sentence
Sender ID correctly showing as your registered header
Step 9 — Select Your Audience
Time required: 2 minutes
In the campaign composer, under Recipients, choose one of:
Existing Contact List — select a list you uploaded previously
Existing Segment — select a filtered segment built from a list
Upload New CSV — upload a one-time list for this specific campaign
Enter Numbers Manually — type or paste up to 100 numbers (for small tests)
DND filter notification (promotional campaigns only): For promotional campaign types, TechTo automatically shows you: "Estimated reach after DND filtering: 8,240 of 10,000 contacts." This tells you how many recipients will actually receive the message before you commit your credits.
Best practice for first-time senders: Before sending to your full list, run a test send to 5–10 of your own numbers (or colleagues' numbers) to verify delivery, personalisation, and sender ID. Under Recipients, choose Send Test and enter the test numbers.
Step 10 — Set Your Send Time
Time required: 1 minute
Under Scheduling, choose one of three options:
Send Immediately — Campaign dispatches the moment you click Confirm. Use for time-sensitive campaigns where every minute of delay reduces impact (flash sales, emergency notices, same-day appointment reminders).
Schedule for Later — Pick a specific date and time. The campaign queues and dispatches automatically at the scheduled time. You can schedule days or weeks in advance.
Recurring Send — Dispatch the same campaign on a schedule: daily, weekly, monthly, or custom. Useful for weekly loyalty reminders, monthly statement notifications, or recurring service alerts.
Timing recommendations for Indian audiences:
Campaign Type | Best Send Window | Why |
Promotional — retail | 11 AM – 1 PM or 7 PM – 8:30 PM | Peak mobile browsing times |
Promotional — food/restaurant | 11 AM – 12 PM or 6 PM – 7 PM | Pre-meal decision windows |
Flash sale launch | 10 AM – 11 AM | Full day buying window ahead |
Appointment reminders | 8 AM – 9 AM (day before) | Morning check-in habit |
Payment reminders | 10 AM or 6 PM | High payment action windows |
Event reminders | 9 AM (day of) or 6 PM (day before) | Planning windows |
Win-back campaigns | 6 PM – 8 PM | Relaxed evening browsing |
Promotional timing restriction: TechTo's scheduler will not allow you to schedule a promotional campaign outside the 9 AM–9 PM window. If you try, the platform displays an error and blocks the schedule. This is a built-in compliance guardrail.
Step 11 — Review and Confirm Before Sending
Time required: 2 minutes
Before the final send confirmation, TechTo shows you a Campaign Summary screen:
Campaign Name: Diwali Sale Blast - Oct 2025
Type: Promotional
Sender ID: 567890
Template: tmpl_promo_diwali_001 (Approved ✓)
Recipients: 8,240 (after DND filter from 10,000)
Segments per msg: 1
Total credits: 8,240
Credits remaining after send: 1,760
Scheduled time: 31-Oct-2025 at 11:00 AM IST
Review every line:
Template status is Approved ✓ — if it shows Pending, do not send. Wait for approval first.
Recipient count looks correct — if it shows 0 or a number far lower than expected, check your audience selection.
Credits remaining after send is positive — if you do not have enough credits, TechTo will prompt you to top up before proceeding.
Scheduled time is correct — double-check AM/PM and timezone.
Click Confirm Campaign. If scheduled, TechTo confirms it is queued. If sending immediately, dispatch begins within seconds.
Step 12 — Monitor Delivery in Real Time
Time required: Ongoing
Once a campaign is dispatched, go to Campaigns → [Your Campaign Name] → Live View.
The live delivery monitor updates every 30 seconds and shows:
Messages sent: 8,240
Delivered: 7,918 (96.1%)
Pending: 182 (2.2%)
Failed: 140 (1.7%)
└ Invalid number: 82
└ Network error: 41
└ Carrier blocked: 17
What "Pending" means: The message has been sent to the carrier but delivery confirmation has not been received yet. This is normal for messages to phones that are switched off or out of coverage. Pending messages are retried for up to 48 hours.
What "Failed" means: Delivery was permanently unsuccessful. The failure reason is shown:
Invalid number — the number does not exist or has been disconnected.
Network error — temporary carrier connectivity issue; TechTo retries automatically.
Carrier blocked — the message was blocked by the carrier, usually due to a DLT mismatch (see Troubleshooting section).
A delivery rate above 95% is excellent. Between 90–95% is typical for a new sender with a recently cleaned list. Below 90% usually indicates list quality issues (outdated numbers) or DLT registration problems.
Step 13 — Read and Interpret Your Campaign Report
Time required: 10–15 minutes after campaign completes
Once a campaign completes (all messages have reached a final status — delivered, failed, or expired), go to Reports → [Your Campaign Name] for the full analytics view.
Delivery Metrics
Metric | What It Tells You | Good Benchmark |
Delivery rate | % of messages that reached the handset | >95% |
DND filtered | Numbers removed before send (promotional only) | Varies |
Failed rate | % of messages that permanently failed delivery | <3% |
Pending expired | Messages still undelivered after 48hr retry window | <1% |
Engagement Metrics (if Link Tracking Enabled)
Metric | What It Tells You | Good Benchmark |
Unique clicks | People who tapped your link | — |
Click-through rate (CTR) | Clicks ÷ Delivered messages | 5–15% for promotional |
Click time distribution | When during the day clicks occurred | — |
Device type | Android vs. iOS split | — |
Enabling link tracking: When composing your message, paste your URL into the message field. TechTo automatically detects URLs and offers to wrap them in a tracked short link. Click Yes, track this link. The original URL is replaced with a TechTo short link (e.g., ttn.ly/abc123) that redirects to your destination and logs the click.
Opt-Out Metrics
Metric | What It Tells You | Warning Threshold |
Opt-outs | Recipients who replied STOP | — |
Opt-out rate | Opt-outs ÷ Delivered | >0.5% = review message relevance |
A high opt-out rate (above 1%) on a campaign is a signal to investigate: Was the message sent to the wrong audience? Was the offer irrelevant? Was the frequency too high? Was the timing intrusive?
Downloading Your Report
Click Export Report for a CSV download containing every message sent, the phone number, delivery status, delivery timestamp, failure reason (if applicable), and click status. This is your audit trail for compliance purposes and your raw data for further analysis.
Step 14 — Common Mistakes Beginners Make (and How to Avoid Them)
The following mistakes account for 90% of delivery failures and compliance issues in first-time bulk SMS campaigns. Read each one carefully.
Mistake 1: Not Completing DLT Registration Before Sending
What happens: Your messages dispatch from TechTo's platform and appear to be sent — but carriers block them before delivery. Your delivery report shows most messages as "Carrier Blocked." You have spent credits on messages no one received. Fix: Complete DLT registration (Steps 3a, 3b, 3c) before sending any commercial message. TechTo flags if your template is pending or unregistered before allowing dispatch.
Mistake 2: Using the Wrong SMS Type for Your Content
What happens: You send a promotional message (a sale offer) using a transactional sender ID. The carrier detects the mismatch and blocks the messages. Worse, it can trigger a TRAI complaint and get your sender ID blacklisted. Fix: Match the content to the type. Promotional content (offers, sales, discounts) → Promotional route. Service content (confirmations, alerts, OTPs) → Transactional route. Never mix.
Mistake 3: Message Content Does Not Match the Registered Template
What happens: You registered a template that says "Get {#var#}% off all orders" but in your campaign you write "Get 40% off all our products." The word "our" is not in the registered template. The carrier detects the mismatch and blocks the message. Fix: Always compose your campaign message by selecting a registered template and filling in only the variable fields. Never edit the static (fixed) text of a template after registration.
Mistake 4: Including a Unicode Character Without Realising It
What happens: You wrote your message in plain English but accidentally included a curly quote ", an em-dash —, or a bullet point •. The encoding switches from GSM-7 (160 chars/segment) to Unicode (70 chars/segment). Your 150-character message becomes a 3-segment message. You are billed 3× what you expected for 8,000 recipients. Fix: Check the encoding indicator in TechTo's composer. If it shows Unicode when you expected GSM-7, scan your message for special characters and replace them with standard equivalents.
Mistake 5: Sending Promotional Messages Outside 9 AM–9 PM
What happens: You schedule a promotional campaign for 9:30 PM thinking recipients will see it first thing in the morning. The messages are blocked at the carrier level. TechTo's scheduler prevents this for manually scheduled campaigns, but some providers allow it — resulting in 100% delivery failure. Fix: Always schedule promotional campaigns to complete dispatch by 8:45 PM to account for queue processing time. TechTo's scheduler enforces this automatically.
Mistake 6: Uploading a Contact List With No Column Headers
What happens: Your CSV file has numbers but no header row. TechTo cannot map the columns correctly, and personalisation tokens fail — every recipient gets {#var#} in their message instead of their name. Fix: Always include a header row in your CSV. First row: mobile,first_name,city (or your column names). Data starts from row 2.
Mistake 7: Not Running a Test Send First
What happens: You send to 50,000 contacts and discover in the delivery report that a personalisation token failure put {#var#} in every message instead of the customer's name. Fix: Always use Send Test with 5 of your own numbers before confirming the full campaign. Verify sender ID, message content, personalisation, and link.
Mistake 8: Ignoring the Opt-Out Trend
What happens: Your first few campaigns have 0.8% opt-out rate. You continue with the same approach. By month 3, you have lost 15% of your list and your delivery rates have dropped because carriers flag your sender ID for high complaint rates. Fix: Monitor opt-out rate per campaign in Reports. Any campaign above 0.5% opt-out rate deserves investigation. Adjust audience targeting, message relevance, or send frequency.
Troubleshooting — Why Are My Messages Not Delivering?
Use this table when delivery rates are lower than expected.
Symptom | Likely Cause | Action |
0% delivery, all "Carrier Blocked" | DLT template not registered or not approved | Check template status in Templates tab. Do not send until status = Approved |
High "Invalid Number" failures | Outdated or incorrectly formatted contact list | Clean list, remove numbers <10 digits, re-upload |
Message shows {#var#} in delivery report | Column mapping error in CSV upload | Re-upload CSV with correct header row, remap columns |
Delivery rate drops suddenly | Sender ID under review or carrier flag | Contact TechTo support. Do not increase send volume while under investigation |
Promotional messages all failing | Sent outside 9 AM–9 PM window | Reschedule within compliant hours |
Message received but truncated | Multi-segment message split at wrong point | Shorten message or restructure to put complete thought within segment boundaries |
Encoding shows Unicode unexpectedly | Special character in message | Find and replace: " → ", — → -, … → ... |
DND numbers receiving promotionals | DND filter not applied | Confirm campaign type is set to Promotional (auto-filters DND). If Transactional type was selected for promotional content, that is a compliance violation |
Advanced: Personalisation at Scale — How Variable Fields Work
Personalisation is the most powerful lever in bulk SMS — but many beginners either skip it or apply it incorrectly.
Here is how personalisation works end-to-end in TechTo:
Your CSV columns:
mobile,first_name,city,last_order_amount,offer_code
9876543210,Rahul,Mumbai,4999,DIWALI25
8765432109,Priya,Chennai,1800,DIWALI15
Your registered DLT template:
"Hi {#var#}, special Diwali offer for {#var#} customers! Spend ₹{#var#}+ and get {#var#} off. Shop: bit.ly/diwali. -567890"
Your column mapping in TechTo campaign composer:
Placeholder 1 → first_name
Placeholder 2 → city
Placeholder 3 → Fixed value: 999
Placeholder 4 → offer_code
What Rahul receives:
"Hi Rahul, special Diwali offer for Mumbai customers! Spend ₹999+ and get DIWALI25 off. Shop: bit.ly/diwali. -567890"
What Priya receives:
"Hi Priya, special Diwali offer for Chennai customers! Spend ₹999+ and get DIWALI15 off. Shop: bit.ly/diwali. -567890"
Two personalised messages. One template. Zero extra effort after setup.
How to Send Bulk SMS for Specific Use Cases
For a Retail Flash Sale
Audience: All active customers (purchased in last 90 days), non-DND, filtered by city if location-specific
Template: Promotional, with {name}, {discount}, {expiry}, {link} variables
Sender ID: 6-digit numeric promotional header
Time: Schedule for 11:00 AM on the sale day
Segment: 1 (keep under 160 chars)
Post-campaign: Check CTR in reports. Create a segment of clickers for a follow-up "last chance" message at 7 PM
For Appointment Reminders (Healthcare/Services)
Audience: Contacts with upcoming appointments (imported from your booking system)
Template: Service Implicit (Transactional), with {name}, {doctor}, {date}, {time}, {address} variables
Sender ID: 6-character alphanumeric (e.g., CLINIC)
Time: Schedule for 8:30 AM the day before the appointment
Add a second send at 8:30 AM on the appointment day itself as the final reminder
Enable two-way messaging to capture CONFIRM/CANCEL replies
For Order Confirmation (E-Commerce)
This is an API-triggered campaign, not a manual bulk send. Connect your order management system to TechTo's API. When an order is placed, your system sends a POST request to TechTo's API with the order details. TechTo sends the confirmation immediately — typically within 2–3 seconds of order placement.
See the TechTo API documentation for the code to trigger transactional messages from your application.
For a Contact List You Are Building From Scratch
Create a TechTo opt-in form: Contacts → Opt-in Forms → Create Form
Customise the form fields (name, mobile, city) and the opt-in confirmation message
Embed the form on your website's homepage, checkout page, and "About" page
Share the opt-in form link in your Instagram bio, WhatsApp broadcast, and email footer
For physical locations, generate a QR code pointing to the form and print it on receipts and signage
For social media: run a "Text OFFER to 9999XXXXXX for 20% off" post and configure the keyword opt-in in TechTo's settings
Frequently Asked Questions
How long does DLT registration take? Business entity (PE) registration takes 2–5 business days. Sender ID and template approvals take 24–72 hours each. Plan for a total of 5–7 business days for full DLT registration before your first send. TechTo's compliance team can expedite this process.
Can I send bulk SMS in India without DLT registration? No. TRAI's DLT mandate requires all commercial SMS senders to be registered. Messages sent without registered templates and sender IDs are blocked by Indian carriers before delivery. There is no workaround.
How many contacts can I upload at once? TechTo supports CSV uploads of up to 500,000 contacts per file. For larger lists, split them into multiple uploads. Enterprise accounts support unlimited total contacts.
What happens to my message if the recipient's phone is switched off? The message enters a pending state. TechTo and the carrier retry delivery for up to 48 hours. If the phone comes back online within that window, the message is delivered. If not, it expires and is marked as "Pending Expired" in your report — and you are not charged for expired messages.
What is the maximum message length? There is technically no maximum — long messages are split into multiple segments automatically. However, each segment beyond the first is billed separately. Best practice is to keep promotional messages to 1 segment (under 160 chars for English, under 70 chars for regional languages).
Can I personalise a bulk SMS with each recipient's name? Yes. Include a first_name column (or any name column) in your CSV. In the campaign composer, map that column to the {#var#} placeholder in your registered template. Every recipient gets their name in the message.
How do I check if a number is on the DND list? TechTo checks DND status automatically for promotional campaigns and removes registered numbers before dispatch. You can also check individual numbers via the DLT portal if needed.
What should I do if my delivery rate is below 90%? First check: Are there "Carrier Blocked" failures? If yes, a DLT issue (template mismatch or unapproved sender ID) is the likely cause. Check template approval status. Second check: Are there high "Invalid Number" failures? If yes, your contact list needs cleaning. Remove numbers that are not 10 digits, disconnected, or formatted incorrectly. Contact TechTo support if the issue persists after these checks.
Can I schedule a promotional bulk SMS for 10 PM to deliver first thing the next morning? No. TRAI regulations restrict promotional SMS delivery to 9 AM–9 PM. TechTo blocks scheduling outside this window for promotional campaigns. Schedule for 9 AM the next day instead.
How do I send bulk SMS in Hindi or Tamil? In the campaign composer, type your message in the regional script. TechTo automatically detects the encoding requirement and switches to Unicode. The segment counter adjusts from 160 chars/segment (GSM-7) to 70 chars/segment (Unicode). Your DLT template must also be registered in the regional script on the DLT portal.
Can I send from an Excel file directly? Save your Excel file as a CSV first (File → Save As → .csv format) and upload the CSV. TechTo does not accept .xlsx files directly.
What is the difference between a campaign report and a delivery receipt? A campaign report is an aggregate view of all messages in a campaign. A delivery receipt (DLR) is an individual confirmation from the carrier that a specific message was delivered to a specific handset. TechTo stores both. Campaign reports are in the Reports section. Individual DLRs are accessible via the API or by exporting the campaign detail CSV.
How do I add the TechTo SMS to my website or app? Use TechTo's REST API. Full documentation, code samples in Python/Node.js/PHP/Java/Go, and a Postman collection are at docs.techtonetworks.com. The API is the same infrastructure that powers the dashboard campaigns.
What Comes Next After Your First Campaign
Sending your first bulk SMS campaign is the beginning, not the end. Here is what to do in the weeks after your first send to improve results continuously:
Week 1 after first send:
Review the delivery report in detail — delivery rate, CTR, opt-out rate
Compare the CTR to industry benchmarks (5–15% for promotional, 10–25% for transactional)
If CTR is low, review the message copy — was the offer specific and compelling? Was the CTA clear?
If delivery rate is low, review the contact list quality and DLT template matching
Week 2–4:
Set up your first automation: an abandoned cart reminder or a post-purchase follow-up sequence
Create a second audience segment and test a different message to a different group
Set up an opt-in form on your website to start growing your list organically
Month 2:
Run your first A/B test: same offer, two different message approaches (one urgency-driven, one benefit-driven)
Set up a recurring campaign for regular communications (weekly offers, monthly statements, fortnightly loyalty updates)
Connect TechTo to your CRM or e-commerce platform via API or native integration for real-time event-triggered SMS
Month 3 and beyond:
Review month-over-month trend in CTR, opt-out rate, and total credited revenue from SMS
Archive underperforming contact segments and increase budget to high-performing segments
Explore TechTo's two-way messaging for customer replies and CSAT surveys
Ready to Send Your First Bulk SMS Campaign?
You now have everything you need to go from zero to your first successful bulk SMS campaign — account creation, DLT registration, list preparation, message writing, compliance, scheduling, and reporting.
Your next step is one click away.
No credit card required. Sandbox available immediately. Full dashboard access from day one.
Need help with DLT registration or campaign setup? → Contact TechTo Support — Free Onboarding Assistance
TechTo Networks — India's Bulk SMS Platform for Beginners and Enterprises. Step-by-step. DLT-compliant. Results from day one.
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