The most intimate channel you can rent
A text message arrives on the same screen as messages from family and friends, often with a notification sound. That is its strength and its danger. Used for something the customer genuinely wants to know now, such as an order update, a back-in-stock alert or a booking reminder, it feels like service. Used for routine promotions, it feels like an intrusion.
Our view is that SMS should be the channel you use least often and most carefully. Treat every message as if the recipient had to pay attention to it immediately, because many of them will.
SMS, WhatsApp or email?
In many markets, and especially in India, SMS competes with WhatsApp and other messaging apps as well as email. Each has a distinct role. The question is not which is best but which suits a particular message.
Fig. 01 · Comparison
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Choosing the channel for a message
Email remains the better home for anything long, considered or worth keeping: newsletters, detailed product stories, receipts and documents. A sensible pattern is email for depth, messaging apps for conversation and SMS for brief, urgent signals. See WhatsApp marketing for the conversational channel.
Consent and regulation come first
SMS is among the most regulated marketing channels. The details differ by country and change over time, so treat what follows as principles and confirm specifics with your provider and legal adviser.
- Explicit consent is generally required for promotional texts. Record when, where and how each person agreed.
- Sender registration is required in many markets. In India, commercial messages run through the telecom regulator's DLT framework, which involves registering the business, sender headers and message templates. Other markets have their own registration schemes.
- Promotional and transactional messages are often treated differently, with different routes, timing restrictions and rules. Classify each message honestly.
- Opt-out must be simple, and opt-outs must be honoured promptly across every system that can send.
- Quiet hours and frequency limits may apply to promotional messages in some markets, and are good practice everywhere.
The messages that earn their place
The best SMS programmes are built on messages customers would be annoyed not to receive. Promotions can work too, when they are genuinely time-sensitive and relevant, but they should be the minority.
- 01Service and transactional: order confirmations, dispatch and delivery updates, appointment reminders, payment confirmations.
- 02Requested alerts: back in stock, price drop on a watched item, ticket release.
- 03Time-critical offers: a sale ending today, sent to people who have shown interest in it.
- 04Recovery: a short cart or payment-failure reminder where the customer has opted in.
- 05Two-way service: confirm or reschedule a booking by replying.
Building an SMS programme
Fig. 02 · Process
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From consent to first send
Writing for a small space
A standard SMS segment holds 160 characters using the basic character set, and fewer when special characters or many non-Latin scripts are used, in which case longer messages are split into multiple segments and may cost more. Every word must work. Identify the sender immediately, state the point, give one action and include the opt-out where required.
Use a recognisable link domain rather than an anonymous shortener, which can look like phishing and may be filtered. In multilingual markets such as India, consider sending in the language the customer chose, accepting the shorter segment length.
Checklist
0/10SMS send checklist
Myth vs reality
SMS myths
Two-way SMS and security
SMS does not have to be one-way. Letting customers reply to confirm an appointment, reschedule a delivery or ask a quick question turns a broadcast channel into a service channel. If you invite replies, someone or something must answer them promptly; an unanswered reply is worse than no invitation.
Security matters more in SMS than in most channels, because fraudsters imitate brands by text. Help customers tell your messages from scams. Use a consistent, registered sender ID; never ask for passwords, card numbers or one-time codes by text; link only to your own recognisable domain; and publish on your website how you do and do not contact customers. These habits protect customers and protect the trust that makes SMS work at all.
Measuring SMS
Track delivery, clicks, conversions, opt-outs and complaints per message type. Use tracked links with UTM parameters so web analytics attribute visits correctly. Because SMS often lands alongside email about the same offer, use holdout groups to see whether the text added anything or simply took credit for an email-driven sale. The email KPIs framework applies with small adjustments.
Planning SMS within the wider programme
SMS works best as a deliberate layer on top of email and messaging apps rather than as a parallel calendar. Map each lifecycle moment to its best channel: email for the welcome story, SMS for the delivery alert, WhatsApp for the support conversation. Then set one frequency cap across all three, and one consent record per channel in the CRM.
Review the mix quarterly. If opt-outs from SMS are rising while email engagement holds, move promotional messages back to email and keep SMS for service. If customers repeatedly reply to texts with questions, that is a signal to offer a conversational channel instead.
Send a text only when you would be comfortable having the customer read it aloud to the person sitting next to them.
Key takeaways
- 01SMS is immediate and intimate, which makes it powerful for urgent moments and damaging when overused.
- 02Use email for depth, messaging apps for conversation and SMS for brief, urgent signals.
- 03Consent, sender registration and honest message classification come before any creative work.
- 04Write for a small space: identify the sender, make one point, give one action and use trusted links.
- 05Measure incrementality with holdouts, because SMS often shares credit with email for the same sale.
Frequently asked
- What is SMS marketing?
- SMS marketing is sending text messages for promotional or informational purposes to people who have agreed to receive them. Common uses include order and delivery updates, appointment reminders, back-in-stock alerts and time-sensitive offers. It is fast and highly visible, and it is regulated in most markets.
- Is SMS marketing legal?
- Yes, when it follows the rules of each market you send to. These typically require explicit consent for promotional messages, simple opt-out, honest classification of messages and, in many countries, sender registration. In India, commercial messaging runs through the telecom regulator's DLT framework. Confirm current requirements with your provider and legal adviser.
- How often should I send marketing texts?
- Sparingly. Set a frequency cap per person that counts SMS, messaging apps and email together, and reserve SMS for urgent or high-value messages. Watch opt-outs and complaints closely; a rise is a signal to send less, or to move some messages to email.
- Is WhatsApp better than SMS for marketing?
- They do different jobs. WhatsApp suits rich, conversational and support messages where the customer uses the app and has opted in. SMS reaches almost any phone and suits short alerts, reminders and one-time passwords. Many businesses use both, coordinated by message type.
- How long can a marketing SMS be?
- A standard segment holds 160 characters in the basic character set and fewer when special characters or many non-Latin scripts are used. Longer messages split into several segments and may cost more. Aim for a single segment where possible, with the sender named first.
Published by Fabulous.Media, a network of specialist marketing agencies. Updated 9 October 2026. Platform features change often; check current official documentation before acting on platform-specific detail.
