OTP SMS India: DLT Compliant One-Time Passcodes for Indian Businesses

The complete guide

OTP SMS India: DLT Compliant One-Time Passcodes for Indian Businesses: everything you need to know

What is OTP SMS India and when should businesses use it?

Short answer: OTP SMS India is a one-time passcode sent by text to an Indian mobile number to verify a login, confirm a signup, approve a transaction or reset a password. Businesses should use it when the customer is already mid-action, such as creating an account, logging in from a new device or confirming a high-value order, because the code is expected and useful.

OTP SMS India is a one-time passcode sent by text message to an Indian mobile number, usually to verify a login, confirm a signup, approve a transaction or reset a password. The message is short, arrives in seconds and works on any phone without an app or internet connection. For Indian businesses, OTP SMS is often the most reliable way to confirm that the person on the other side is who they say they are.

Use OTP SMS when the customer is already in the middle of an action: creating an account, logging in from a new device, confirming a high-value order or resetting a password. Because the customer started the action, an authentication message is expected and useful. Keep the message focused on the code and the context, and avoid adding offers or promotions to an OTP, since that confuses the category and the customer.

Com.Bot offers OTP SMS only in India and only as a one-way channel. The business sends, the customer receives. There is no reply keyword, no STOP reply and no SMS inbox. If a customer needs to respond, your OTP message can include a support phone number or a wa.me WhatsApp link so the conversation moves to WhatsApp, where two-way messaging is supported.

• Login and signup verification for apps, portals and websites
• Password reset and new device confirmation
• High-value order or payment confirmation
• Account change verification such as a new phone number or email
• Delivery or service confirmation where a code is required
• Government and utility portals that need identity verification

Why OTP SMS still works on this channel

Short answer: OTP SMS works because it reaches every mobile phone in India without an app, data plan or smartphone. Under TRAI rules, OTP and service messages are delivered to all numbers, including DND numbers, since they are not promotional. Com.Bot runs OTP SMS alongside WhatsApp, Instagram, Messenger, Google RCS and web chat in one account.

SMS reaches every mobile phone in India without an app, a data plan or a smartphone. That makes it the most universal verification channel for Indian businesses, from a D2C brand onboarding a new customer to a government body confirming a citizen login. An OTP arrives in seconds and the customer can read it on the lock screen, which keeps the verification step short.

Authentication messages are also treated differently under TRAI rules. OTP and service messages can be delivered to all numbers, including numbers on the DND registry, because they are not promotional. That means a customer who has opted out of marketing SMS can still receive the OTP they need to log in. This is one reason OTP SMS remains a core part of Indian digital infrastructure.

Com.Bot processes 100M+ messages a day across channels and works with 100+ government bodies, so the platform is built for high-volume, time-sensitive messages. OTP SMS runs alongside WhatsApp, Instagram, Messenger, Google RCS and web chat in one Com.Bot account, which means your team can manage verification and customer conversations from the same inbox.

• Works on every mobile phone, no app or internet needed
• Delivered to DND numbers because OTP is not promotional
• Fast delivery for time-sensitive logins and payments
• One account for OTP SMS and WhatsApp Business API
• Shared team inbox for support follow-ups after the OTP
• Reporting on delivery so you can spot issues early

How to set up OTP SMS in India on Com.Bot

Short answer: To set up OTP SMS in India on Com.Bot, first complete DLT registration of your business entity, a 6-character sender ID such as LUMASK, and each OTP template using {#var#} variables. Then connect SMS in Com.Bot and trigger OTPs from your system. Since SMS is one-way, add a support number or wa.me link for replies.

Setup starts with DLT registration, which is a TRAI requirement for any business sending SMS in India. You register three things: the business entity, the sender ID (also called the header, a 6-character name such as LUMASK) and every message template you plan to send. Each template is registered under a category: promotional, transactional or service, or OTP. For OTP messages, the category is OTP, and the template uses {#var#} variables for the code and any context.

Once your entity, header and templates are approved on the DLT platform, connect your Com.Bot account and add SMS as a channel. In Com.Bot you can trigger an OTP from your own system using the automation builder, an API call or a webhook, and the platform sends the registered template from your approved sender ID. Because SMS on Com.Bot is one-way, the template should include a support phone number or a wa.me WhatsApp link if the customer may need to respond.

After the first OTP is live, test delivery across networks and check the reporting in Com.Bot. Keep a small set of approved OTP templates for common flows such as login, signup, password reset and payment confirmation. When you change the wording, register the new version on DLT before sending, since the message must match the approved template.

• Register your business entity on a DLT platform
• Register a 6-character sender ID such as LUMASK
• Register each OTP template with {#var#} variables
• Choose the OTP category for one-time passcodes
• Connect SMS in Com.Bot and trigger OTPs from your system
• Add a support number or wa.me link for replies

DLT, DND and the rules for OTP SMS India

Short answer: DLT registration is mandatory for SMS in India: the business entity, sender ID and every template must be registered, with OTP templates using the OTP category and {#var#} variables. DND rules apply to promotional SMS only, so OTP and service messages reach DND numbers. SMS on Com.Bot is one-way, with no reply keywords.

DLT registration is mandatory for SMS in India. The business entity, the sender ID and every template must be registered before sending. Templates use {#var#} variables, and the message category must match the content. OTP messages are authentication messages, service and transactional messages cover updates about an existing order or account, and promotional messages cover offers and re-engagement. Sending an OTP under the wrong category can get the template rejected or the sender ID flagged.

DND rules apply to promotional SMS only. Promotional messages go only to numbers not on the DND (NCPR) registry and within TRAI-permitted hours. Service and OTP messages can go to all numbers, including DND numbers, because they are not promotional. This is why an OTP reaches a customer who has opted out of marketing SMS, and why you should never mix an offer into an OTP template.

SMS on Com.Bot is one-way. Customers cannot reply to the SMS, so there are no reply keywords, no STOP replies and no two-way SMS chat. If a customer needs to respond, include a phone number or a wa.me WhatsApp link in the message. SMS is simply another channel the business chooses to use, and WhatsApp is where the two-way conversation happens.

• Entity, sender ID and templates must be DLT registered
• OTP templates use the OTP category and {#var#} variables
• Promotional SMS goes only to non-DND numbers in permitted hours
• Service and OTP SMS can reach DND numbers
• SMS on Com.Bot is one-way, with no reply keywords
• Point customers to WhatsApp or a phone number for replies

OTP SMS versus WhatsApp, RCS and other channels

Short answer: OTP SMS is best for reaching any Indian mobile number, including DND numbers and customers without WhatsApp. WhatsApp Business API suits flows where the customer replies or taps buttons, and Google RCS adds branded rich messages on supported Android phones. Com.Bot runs all these channels in one platform, so you pick per use case.

OTP SMS is the right choice when you need to reach any Indian mobile number, including customers who do not use WhatsApp or who are on a basic phone. It is also the right choice when the customer is on a DND number and you need to send a verification code. SMS is plain text, 160 GSM characters per segment, so keep the message short and put the code near the start.

WhatsApp Business API is a better fit when the customer needs to reply, when the message includes buttons or a richer layout, or when you want the verification to lead into a conversation. WhatsApp authentication templates are a separate category, and replies inside the 24-hour customer service window are free-form. Google RCS Business Messaging adds a branded sender with a logo and verified badge, images, carousels and suggested reply buttons on supported Android phones, and brands need agent verification before launch.

Many Indian businesses use both: OTP SMS as the universal option for verification, and WhatsApp for the follow-up conversation, order updates and support. Com.Bot runs WhatsApp, Instagram, Messenger, Google RCS, SMS and a website chat widget in one platform, so you can choose the channel per use case without managing separate vendors. If a customer replies to an OTP SMS, the wa.me link in the message opens WhatsApp and the conversation continues there.

• Use OTP SMS for universal reach and DND numbers
• Use WhatsApp when the customer needs to reply or tap a button
• Use RCS for branded, rich messages on supported Android phones
• Keep OTP SMS plain text and under 160 characters per segment
• Add a wa.me link so replies move to WhatsApp
• Run all channels from one Com.Bot account

Mistakes to avoid and how to measure OTP SMS results

Short answer: The biggest OTP SMS mistake is mixing promotional content into an OTP template, which breaks the category and can get it rejected. Also register every new template version on DLT before sending, and remember SMS is one-way, so include a phone number or wa.me link for replies. Track delivery rate, delivery time and verification success.

The most common mistake is mixing promotional content into an OTP template. An offer, a discount or a re-engagement line turns an authentication message into a marketing message, which breaks the category and can get the template rejected. Keep OTP templates focused on the code and the context. Another common mistake is forgetting to register a new template version on DLT before sending, which causes the message to fail or the sender ID to be flagged.

A third mistake is treating SMS as a two-way channel. Customers cannot reply to the SMS, so there are no reply keywords and no STOP replies. If your message asks the customer to reply, they cannot. Always include a phone number or a wa.me WhatsApp link when a response is needed. Also avoid sending OTPs to numbers that did not request them, and never use OTP templates for promotions, since that damages trust and can affect your sender ID.

To measure results, track delivery rate, time to delivery and verification success rate for each OTP flow. In Com.Bot you can see delivery reporting and compare OTP SMS with WhatsApp authentication templates for the same flow. If delivery is slow on one network, test another route. If customers often need help after the OTP, add a wa.me link and route the conversation to your shared team inbox so agents can respond inside the 24-hour window.

• Do not add offers or promotions to OTP templates
• Register every new template version on DLT before sending
• Do not expect replies to the SMS, since it is one-way
• Include a phone number or wa.me link when a reply is needed
• Track delivery rate, delivery time and verification success
• Compare OTP SMS with WhatsApp authentication for each flow

Costs of OTP SMS India on Com.Bot

Short answer: OTP SMS on Com.Bot is billed in two parts: the quarterly plan plus separate SMS message charges. India plans are Silver at ₹10,000 per quarter, Gold at ₹23,000 and Platinum V1 at ₹1,80,000. SMS charges depend on category and recipient country, so ask the Com.Bot team for current OTP SMS rates in India.

Com.Bot plans are priced per quarter, every three months, never per month. In India, Silver is ₹10,000 per quarter, Gold is ₹23,000 per quarter and Platinum V1 is ₹1,80,000 per quarter. Gold is the recommended plan for growing businesses, with 10 team members, a bot builder up to 30 blocks, 2M bot triggers and support in 6 working hours. Platinum V1 adds 3 WhatsApp API channels, 5M contacts, 25 team members and support in 2 working hours.

SMS message charges are billed separately from the plan, based on the message category and the recipient's country. For current OTP SMS rates in India, ask the Com.Bot team for the latest pricing. Add-ons are available if you need more team members, social channels, ecom stores, external actions or bot triggers. Expert help is available at ₹2,500 or ₹5,000 per hour depending on the topic.

Payments are non-refundable, and you can cancel anytime with service running to the end of the billing period. Com.Bot accepts cards, UPI, PayPal, crypto and bank transfer for plans. To get started, sign up at https://v3.com.bot/register, or talk to the team on WhatsApp at +91 080 6987 1810 or by email at sales@com.bot.

• Silver ₹10,000 per quarter, Gold ₹23,000, Platinum V1 ₹1,80,000
• SMS message charges billed separately from the plan
• Ask the Com.Bot team for current OTP SMS rates in India
• Add-ons for extra team members, channels, actions and triggers
• Expert help at ₹2,500 or ₹5,000 per hour
• Cards, UPI, PayPal, crypto and bank transfer accepted for plans

Frequently asked questions