How to Send Bulk SMS in India: Step-by-Step Guide With Free DLT Support

To send bulk SMS in India, create a free account on Fast2SMS (₹50 test credit is added at signup), register your business, sender ID and message templates on a DLT portal with Fast2SMS's free DLT support, then upload your numbers from Excel or CSV and send or schedule the campaign from the panel or the API. OTPs and service updates reach every number at any time, while promotional SMS reach only Non-DND numbers between 10 am and 9 pm. If you have to send before your DLT approval arrives, Quick SMS works without DLT.

This guide walks you through the whole process in plain words, from the first click to reading your delivery report. It is written for shop owners, schools, clinics, online stores, startups and developers who want to get it right the first time.

What bulk SMS is and what you need before you start

Bulk SMS means sending one message, or one personalised template, to hundreds or lakhs of mobile numbers at once from a web panel or an API instead of typing on a phone. Businesses use it for login OTPs, order and delivery updates, fee and EMI reminders, appointment alerts, attendance notices and festival offers. An SMS needs no internet connection and no app on the customer's phone, so it reaches every handset in India, from the newest smartphone to a basic feature phone.

In India every business SMS passes through a system called DLT, which TRAI (the Telecom Regulatory Authority of India) made compulsory to cut down spam and fraud. That changes how you start. Before your first campaign, three things must be registered: your business, the sender name customers will see, and the exact wording of each message. It sounds like paperwork, and it is, but it is done once, and Fast2SMS helps you through it without any charge.

Your checklist

• A mobile number and email address for your Fast2SMS account.
• Business documents for DLT: a PAN card, a GST certificate or another business proof, an address proof and an authorisation letter on your company letterhead.
• An idea for a six-character sender name (called a header) that clearly matches your brand.
• The messages you plan to send, written once as templates, with the changing parts (name, amount, date) marked as variables.
• Your customers' numbers in an Excel or CSV sheet.
• A small recharge, from ₹100, when you are ready to send beyond the free test credit.

The five steps at a glance

The order matters. Many first-time senders recharge, upload a list and only then discover that nothing can go out without an approved template. Follow the steps in sequence and you will usually be sending within a few working days of signing up, with Quick SMS available in between if something cannot wait.

Step 1: Create your free Fast2SMS account

1. Open the signup form. Go to fast2sms.com and choose Signup. You register with your mobile number, which is verified with an OTP.
2. Add your basic details. Your name and email are enough to begin. You can add your GSTIN later in Settings so it is printed on recharge invoices.
3. Collect the free credit. ₹50 is added to your wallet automatically. No card is needed, and there is no time limit on the test credit. At the default rate of ₹0.25 per SMS, that covers about 200 test messages.
4. Look around the panel. You will find DLT SMS, Quick SMS, Dev API, Delivery Reports and Transaction History, along with WhatsApp, RCS and Voice in the same account and the same wallet.

The account itself costs nothing. There is no setup fee, no monthly rental and no minimum commitment. You recharge only when you want to send more than the test credit allows, starting from ₹100.

Step 2: Register on DLT with free help from Fast2SMS

DLT in plain words

DLT stands for Distributed Ledger Technology. In practice it is a shared, blockchain-based register run by the telecom operators under TRAI's rules. Your business registers on it once as a Principal Entity. You then register your headers (sender IDs) and your content templates (message wording). Every time you send, the operator checks that the header and the text match what you registered. A message that does not match is blocked.

All operator portals share the same data, so you register on any one of them and your entity ID works everywhere. You do not send SMS from the DLT portal; you only register there. Sending still happens from your Fast2SMS panel or API.

This guide keeps DLT short on purpose. For the full walkthrough with portal screenshots, read Fast2SMS's DLT registration guide.

Which portal to use, and what it costs

The DLT portals are run by Jio (TrueConnect), Vi (Vilpower), Airtel, BSNL, Videocon (Smartping) and Tata Teleservices. Fast2SMS's DLT guide recommends Jio because registration there is free, and its DLT FAQ also lists BSNL and Videocon as free portals, while the Vi portal charges ₹5,900. These fees belong to the operators and can change, so confirm the amount on the portal when you register. Fast2SMS does not charge anything for helping you.

Documents you will need

• Identity proof: PAN card.
• Address proof: passport, voter ID or driving licence.
• Business proof: GST registration, certificate of incorporation, TAN, trade licence or company PAN card.
• Letter of authorisation: on your company letterhead, signed by the owner, naming the person who registers on the company's behalf.

On the Jio portal each uploaded file must be smaller than 5 MB. Make sure the business name, address and signatory details are identical across all documents. Mismatched details are the most common reason an entity application is rejected.

How long it takes

After you submit, the operator verifies your details and emails you the entity ID. Fast2SMS's Jio guide mentions about two to three days for entity approval, and its DLT FAQ says three to five working days. Header approval can take a few more working days on top of that. While you wait, you can draft your templates and prepare your contact list, so nothing is wasted.

Link Fast2SMS as your telemarketer

Once your entity is active, log in to the DLT portal and bind Fast2SMS to your entity, which the portals call PE-TM binding. On Jio, open Campaign, then My Telemarketer, then Manage Telemarketer, search for SID GROUPS, drag that row into your telemarketer table and click Apply. The telemarketer name and ID for each portal are listed on the DLT registration page, and the telemarketer guide for Jio shows each click.

What free DLT support covers

The Fast2SMS team walks you through entity, header and template registration on the operator portal and reviews your template wording before you submit it, which avoids most rejections. You can ask in the panel chat, call +91 6262778822, email [email protected] or book a free call at fast2sms.com/meet. Many senders simply send their draft templates to support first and submit only after the review.

Choose the right SMS route before you register templates

When you register a template you pick a category, and that category decides who receives the message and when. Choose wrongly and an important message will quietly fail to reach customers who have DND switched on. Decide the route first, then write the template.

OTPs deserve a special mention. On Fast2SMS they travel on priority routes and usually reach the handset in one to two seconds. If you send OTPs from an app or website, look at Smart OTP, which can fall back to WhatsApp automatically when an SMS is not delivered.

Step 3: Get your sender ID and templates approved

Sender ID (header) rules

• A header has exactly six characters and must represent your brand or company name.
• Headers for informative routes (Transactional, Service Implicit, Service Explicit) use six letters only, with no numbers, for example FSTSMS.
• Promotional headers have traditionally been six digits, with the first digit set by your business category (for example 3 for education and 4 for healthcare). Fast2SMS's newest template library notes that promotional templates can now use your alphanumeric brand header, so ask DLT support which rule your portal applies today.
• Headers are case-sensitive: FSTSMP, fstsmp and Fstsmp are three different headers.
• Names of celebrities, politicians, other companies' trademarks or government bodies are refused. If your header does not resemble your entity name, keep documents ready that show the connection.
• A registered header has lifetime validity, but it is cancelled if it stays unused for more than 90 days.

Step-by-step screens are in the header registration guide for Jio.

Writing a content template

A content template is your message with fixed text plus placeholders (variables) for the parts that change for each customer. The operator compares every outgoing SMS with the approved template, so the fixed words must stay exactly the same each time.

Good templates follow a few simple habits:

• End the message with your company or brand name. Templates without it may be rejected.
• Keep one clear purpose per template. A school might register separate templates for attendance, fee reminders and exam dates.
• Stay within 160 characters for English (70 for Hindi and other Unicode scripts) where possible, because longer messages are sent and charged as multiple parts.
• Prepare a sample message with realistic values for every variable. New registrations ask for one, and it must mirror the template exactly.

The variable tags required since January 2026

Templates used to mark every variable with a single generic tag, {#var#}, which let anything be inserted. Under the newer rule, templates created after 14 January 2026 must use typed tags, and a value that does not fit its tag can make delivery fail. Fast2SMS's article on the 2026 variable tagging rules explains the change, including the 60-day window given to older templates.

Two rules catch many people out. First, links and phone numbers used in {#url#}, {#urlott#} or {#cbn#} must be registered as call-to-actions for the template, otherwise they fail even on an approved template. Second, only {#alphanumeric#} variables may sit next to each other; every other tag needs fixed text between variables. The variable tagging reference has the details, and the sample SMS templates library has ready wording for OTPs, stores, schools, appointments and offers.

Example templates by business

Replace BRAND with your own name, then submit each template on the portal under Template, Content Template Registration. Once approved, it moves to the Registered tab with its template ID. The guide on getting a DLT template ID shows exactly where that ID appears.

Add your approved details to Fast2SMS

1. Entity. In the DLT SMS section of your panel, add your entity name and entity ID exactly as shown on the DLT portal, with a screenshot. Copy and paste instead of typing to avoid errors.
2. Sender IDs. Add only headers that are already approved and active on the portal, with a screenshot of the Registered tab. Pending headers are not accepted.
3. Templates. Add each approved template ID, its category and the exact text, again with a screenshot.
4. Verification. The Fast2SMS team matches your entries against the screenshots. Once activated, each template appears under the sender IDs it was registered with, ready to pick when you compose.

Step 4: Prepare and upload your contact list

With templates approved, the remaining work is the same for every campaign. Start with a clean list:

• One number per row, as a 10-digit Indian mobile number, in an Excel or CSV sheet.
• Extra columns for variables. Add columns for the values your template needs, such as customer name, order number or amount. In the panel you map each column to a template variable, and every row gets its own personalised message.
• Remove duplicates and wrong numbers before uploading, so you do not pay for messages that cannot be delivered.
• Use groups. Save regular lists (all parents, all members, Mumbai customers) in the address book. Groups can be reused across SMS, WhatsApp and RCS campaigns.
• Message only people who know you. For promotional campaigns, consent matters under DLT, and a relevant list also gives better results.

For a handful of numbers you can simply paste them into the number field. For thousands, upload the sheet.

Step 5: Send now or schedule, then track delivery

1. Open DLT SMS in the panel and choose your approved sender ID.
2. Pick the template. Only templates mapped to that sender ID are listed.
3. Add the numbers by pasting them, uploading your sheet or choosing a saved group, and map the sheet's columns to the template variables.
4. Check the live preview. It shows the final SMS exactly as a customer will see it, with the character count and the number of parts.
5. Send now or schedule. To schedule, pick a date and time; the campaign goes out then. Pending scheduled campaigns can be cancelled from the panel before they start.
6. Confirm and watch the delivery report fill in.

Message length and languages

A standard English SMS holds 160 characters. Hindi, Marathi, Gujarati, Tamil, Telugu, Kannada, Bengali, Malayalam, Punjabi, Odia and other scripts are sent as Unicode SMS, where one part holds 70 characters. Longer messages are split into parts, and each part counts as one SMS, so a 200-character English message costs two SMS per number. The live counter in the panel shows this before you send.

Reading delivery reports

Every campaign shows each number with its status (sent, delivered or failed) and the time the message reached the handset. Failed messages carry the reason the operator returned, so you can act instead of guessing. You can search a number, filter by status and export the report to Excel. If you use the API, the same data can be pushed to your server by webhook, and every debit appears in Transaction History with the campaign and amount.

Sending bulk SMS from your website, app or CRM (API)

If your messages are triggered by software, such as an order system, a billing tool or a login screen, use the API instead of the panel. Your API key is in the Dev API section of the panel. That page also builds a ready request URL for each approved template: you only change the numbers and variable values.

curl -X POST "https://www.fast2sms.com/dev/bulkV2" \
  -H "Authorization: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"route":"dlt","sender_id":"FSTSMS","message":"111111",
       "variables_values":"Rahul|4821|1299",
       "numbers":"9999999999,8888888888"}'

• route: dlt for DLT SMS, or q for Quick SMS.
• sender_id: your approved six-letter header.
• message: the message ID of your approved template, shown in Dev API.
• variables_values: the values for the template's variables, separated by a pipe (|).
• numbers: a comma-separated list; hundreds per call is fine for bulk sends.
• schedule_time: optional, to send later, in DD-MM-YYYY-HH-MM format.

The API costs the same per SMS as the panel, and there is no API fee or monthly charge. Delivery status reaches your server through webhooks, or you can fetch it by request ID with the delivery report API. Full reference and code samples for PHP, Node, Python, Java and .NET are at docs.fast2sms.com, and the bulk SMS API guide walks through real requests. For OTPs, the dedicated send and verify endpoints generate and check the code for you, so your app never stores OTPs.

Not a developer? Free plugins connect Fast2SMS to WordPress and WooCommerce, Shopify and TallyPrime, and connectors exist for Zapier, Pabbly and many CRMs. Your approved templates appear inside them as dropdowns.

No DLT yet? Send with Quick SMS

DLT approval takes days, but sometimes a message must go out today. Quick SMS fills that gap. It delivers to Indian mobile numbers through an international gateway instead of the domestic DLT system, so you need no registered entity, header or template.

• Open text. Write the message you need; there is no pre-approved wording.
• DND and Non-DND. Quick SMS reaches every Indian number on all operators, including DND numbers.
• Any hour. There is no 9 pm cut-off on this route.
• Numeric sender. Customers see a numeric international sender, not your six-letter brand header.
• Reviewed before release. The Fast2SMS team checks each campaign for spam and fraud. Up to three campaigns can wait for review at a time, and accounts whose campaigns are repeatedly rejected lose the route for 15 days.
• Unlocked after one recharge. The route opens after your first recharge of ₹100 or more. Its flat per-SMS rate is higher than DLT SMS and is shown in the panel before you confirm.
• Same API. Use the same bulkV2 endpoint with route=q. See also API SMS without DLT registration.

Quick SMS is meant for urgent, one-off and pre-DLT sending. Personal messages, spam, prize or loan bait and impersonation are not allowed. For regular sending, finish DLT and move to DLT SMS for a much lower price and your own brand name.

DND, consent and timing rules for promotional SMS

DND (Do Not Disturb) lets mobile users block promotional messages. Under TRAI's rules, customers control their own preferences: they can give or withdraw consent and complain about unwanted messages, and operators act against senders who break the rules. In practice:

• Promotional SMS go only to Non-DND numbers and only between 10 am and 9 pm. A consent template must be registered before sending promotional or Service Explicit messages.
• Transactional and Service Implicit SMS reach DND numbers too, at any hour, and need no consent template. They must stay informative; sneaking an offer into an order update breaks the rules and risks rejection.
• Timing still matters for informative messages. A fee reminder at 7 am annoys parents even though it is allowed.
• Always identify yourself with your brand name, and give opt-out instructions in marketing messages.

Learn more on Fast2SMS's DND page. If your offers keep hitting the DND wall, consider WhatsApp Business API or RCS messages for marketing, and keep SMS for OTPs and updates.

What bulk SMS costs on Fast2SMS

Pricing is prepaid and simple. At the time of writing, the default rate is ₹0.25 per SMS for recharges between ₹100 and ₹3,999, and the per-SMS rate falls as the recharge grows, down to ₹0.11 per SMS on the largest slab. The full slab table, with how long each discounted rate stays valid, is on the bulk SMS pricing page. A few points to plan your budget:

• One rate for every DLT category. Promotional, transactional, Service Implicit, Service Explicit and OTP SMS cost the same, from the panel, a plugin or the API.
• The wallet never expires. Validity applies only to a discounted rate; after it ends, the default rate applies to the remaining balance.
• GST. 18% GST is added on the recharge amount, and a GST invoice is generated for every payment.
• Parts count. A message longer than one part is charged per part.
• No other fees. No setup fee, no monthly rental and no charge for DLT help. Operator DLT portal fees, where any apply, are paid to the operator.
• High volume. If you send lakhs of SMS a month, contact sales through the pricing page or contact us for a custom rate.

A quick example: 10,000 single-part SMS at the default ₹0.25 rate cost ₹2,500 plus GST. A ₹4,000 recharge at ₹0.21 per SMS buys about 19,047 SMS.

Common mistakes that stop bulk SMS from delivering

1. Informative messages registered as Service Explicit or Promotional. They then miss every DND number. Register OTPs as Transactional and other updates as Service Implicit.
2. Sent text that does not match the template. An extra word, a changed spelling or a missing full stop is enough for the operator to block it. Copy the approved text; never retype it.
3. Wrong variable tags or values that are too long. A link in an {#alphanumeric#} slot, or an unregistered link in {#url#}, fails under the new rules.
4. Header not matching the brand. Unrelated or famous names are rejected; keep your header close to your business name.
5. Missing brand name at the end of the template. Add it to every template before submitting.
6. Promotions after 9 pm or to DND lists. They will not be delivered. Schedule offers inside the window and accept that DND numbers are out of reach on this route.
7. Letting a header go unused for 90 days. It gets cancelled. Send at least occasionally, or register again when needed.
8. Typing entity or template IDs by hand in the Fast2SMS panel. One wrong digit holds up approval. Copy and paste.
9. Ignoring failure reasons. Keep cleaning invalid numbers from your lists after each campaign.
10. Buying a big pack before testing. Use the ₹50 credit and a ₹100 recharge first; there is no pack to buy here anyway.

Tips for bulk SMS campaigns that get results

• Segment your list. Group customers by purchase history, location or interest and send each group a message that fits it.
• Send at sensible hours. Working hours get attention; very early or very late messages push people to opt out.
• Give one clear action. A link, a phone number or a store address tells the customer exactly what to do next.
• Keep it short. Simple words and one idea per message. One part is cheaper and easier to read.
• Personalise with variables. A name and an order number make a message feel written for the reader.
• Measure and adjust. Compare delivery and response across campaigns and reuse what worked.
• Ask for feedback after a purchase or visit, and include opt-out directions in marketing messages.
• Combine channels. The Campaign flow builder can send SMS first, then WhatsApp, RCS or a voice call depending on delivery, with delays between steps.

Fast2SMS's article with bulk SMS marketing tips for beginners adds a checklist of do's and don'ts.

Why businesses choose Fast2SMS for bulk SMS

• Since 2011. More than 15 years in Indian business messaging, with over 5 million registered users according to Fast2SMS.
• Free DLT support. Help with entity, header and template registration, including a review of your template wording before you submit.
• Reports you can act on. Per-number status with delivery time and the operator's reason for every failed SMS, exportable to Excel and available by webhook.
• An easy panel. Sender IDs and templates mapped automatically, a live preview, Excel and CSV upload, groups and scheduling.
• A simple API. One request to send, webhooks for status, and code samples in every major language.
• Fair pricing. Recharge from ₹100, no monthly fee, rates down to ₹0.11 per SMS on volume, and ₹50 free credit to test.
• Quick SMS for the days before DLT approval, from the same account and wallet.
• One account, every channel. Bulk SMS, OTP, WhatsApp Business API, RCS and voice calls share one balance and one address book.
• Security and uptime. ISO 27001, SOC 2 Type 2 and regular VAPT, with 99.9% uptime.
• Real people for support on chat, phone (+91 6262778822), email and free scheduled meetings at fast2sms.com/meet.

Ready to start? Create your free account at fast2sms.com, send your draft templates to DLT support, and your first campaign can go out as soon as the approvals land.