Messaging 101: marketing in the chat, from SMS to WhatsApp

Messaging marketing is talking to customers in the apps they already use to talk to each other. It covers the old text message (SMS), its richer successor RCS, and the chat apps: WhatsApp, Messenger, Instagram Direct, Telegram, LINE and others. For a marketer the difference from email is intimacy: a message lands next to messages from family, so permission and relevance matter even more.

• What it is: offers, reminders, updates and two-way conversations sent to people who have agreed to receive them.
• Who runs it: mobile operators carry SMS and RCS; the app owners (Meta, Telegram, LY Corporation and others) set the rules on their platforms⁵⁷⁹.
• Who may start: on SMS the business, with consent¹⁵; on WhatsApp the business, with an opt-in and an approved template⁴⁵; on Messenger, Instagram and Telegram mostly the person⁷⁹.
• How it is priced: WhatsApp charges per delivered template message, by category and country¹; SMS is priced per message by the provider you use.
• Best for: conversion, retention and loyalty, event promotion and lead generation through conversations.
• Weak for: reaching strangers; cold outreach breaks both the law and the platforms' rules.
• As of: October 2026.

Permission. Before the first marketing message, the person must have agreed. WhatsApp requires businesses to obtain an opt-in that clearly names the business; the opt-in may be general rather than WhatsApp-specific, as long as local law is respected, and Meta recommends asking separately for each category of message, such as order updates or offers⁴. In the United States, the operators' trade body CTIA expects senders to get consent whether or not the law applies, to build their own lists rather than renting them, and to keep records of each opt-in; a consent applies only to the campaign and sender it was given for¹⁵.

Templates and windows. On WhatsApp a business may start a conversation only with a message template approved in advance. When the customer writes, a 24-hour customer service window opens, and resets with each new message from them; inside it the business may reply freely, outside it only templates are allowed⁵. Templates fall into marketing, utility and authentication categories, and only authentication templates may carry one-time passcodes¹. Messenger and Instagram work from the person's message: the business has 24 hours to reply, and those replies may include promotional content⁷. After that, message tags cover a few approved cases, cannot carry promotions, and a human agent tag lets staff reply within 7 days⁷⁸. Telegram bots cannot start a conversation at all; the person must write first or add the bot to a group⁹.

Starting the conversation. The best messaging programmes let the customer begin. Meta's click-to-message ads open a one-to-one chat with the business on Messenger, Instagram or WhatsApp, and a multi-destination option sends each person to the app where they are most likely to reply⁶. QR codes, website buttons and packaging do the same off Meta's ads.

RCS. Rich Communication Services is the operators' successor to SMS. Apple added RCS in iOS 18 in September 2024¹¹, and in May 2026 began rolling out end-to-end encrypted RCS between iPhone and Android in beta, with iOS 26.5, supported carriers and the latest Google Messages¹².

The first text message was sent on 3 December 1992, from a computer over Vodafone's UK network: "Merry Christmas"²⁴. Since 1 July 2025 WhatsApp has billed per delivered message, replacing its earlier per-conversation model¹³.

Regulation followed the money. India's TRAI set out its Telecom Commercial Communications Customer Preference Regulations in 2018 and amended them in February 2025¹⁶ and again in September 2026¹⁷. In the United States, the FCC ruled in February 2024 that people may revoke consent to texts by any reasonable means¹³.

Each region has its favourite channel, so the plan starts with the audience, not the app.

• Americas. In the United States, marketing texts are governed by the TCPA, enforced by the FCC, and by the operators' CTIA principles¹³¹⁵.
• Europe. The EU applies the same prior-consent rule to SMS and similar messages as to email, since the ePrivacy Directive was amended in 2009²¹; the UK's PECR rules on electronic mail cover texts too²⁰.
• Middle East and Africa. In the UAE, brands must register sender names and upload their consent records on the operators' consent management platform before sending marketing SMS¹⁸.
• Asia-Pacific. India regulates commercial SMS through TRAI¹⁶, and LINE is the leading chat app in Japan, Thailand and Taiwan: LY Corporation counted 100 million monthly active users in Japan, 54 million in Thailand and 22 million in Taiwan at 31 March 2026²³.

WhatsApp's scale is global: Meta reported more than 2 billion daily active users for WhatsApp, and said paid messaging had passed a $2 billion annual run-rate, on its fourth-quarter 2025 call²². Check each country's data before you plan.

• Conversion and conversational commerce: questions answered, products shown and orders taken in the chat, often started by a click-to-message ad⁶, common in retail and e-commerce.
• Lead generation: qualifying a prospect in a few messages, then handing over to sales, for real estate, automotive and education.
• Retention and loyalty: order and delivery updates, renewal reminders and member offers, linked to CRM and loyalty.
• Event promotion: reminders before the day and directions on it, cutting no-shows in hospitality and travel.
• Service that sells: replies inside the 24-hour window may include promotional content on Messenger and Instagram⁷, so a support question can become a chance to recommend.

• WhatsApp. Since 1 July 2025 Meta charges for each delivered template message, at a rate set by the message's category (marketing, utility or authentication) and the recipient's country; messages from users to businesses are not charged, utility and authentication messages have volume tiers, and Meta changes prices only on the first day of a quarter¹. From 1 October 2026 Meta also charges per message for utility messages sent in reply inside an open 24-hour window¹². The rate card is on Meta's pricing page.
• Messenger and Instagram. The cost is mostly the ads that start conversations⁶ and the team or tools that answer them.
• Telegram. Sponsored messages are bought on the Telegram Ad Platform, in public channels with 1,000 or more subscribers; Telegram shares 50% of that ad revenue with the channel owners¹⁰.
• SMS and RCS. Priced per message by the provider, varying by country and by sender type. Ask for the official price list for each market.

Count the conversation, not only the send. A cheap message that starts nothing is expensive; a template that leads to a sale is not. Track cost per conversation, conversion rate and cost per acquisition.

This is a summary, not legal advice. Two layers apply: national law and the platform's policy.

• United States. The FCC's 2024 order says consent to robocalls and robotexts may be revoked by any reasonable means and must be honoured within 10 business days; a single confirmation text without marketing is allowed¹³. In 2026 the FCC said it is modifying the rules to let senders designate an exclusive means for revoking consent, and asked whether seven business days would be a reasonable deadline¹⁴; check the final text before relying on either. CTIA adds that the call to action should name the programme, the sender, any fees and how to opt out¹⁵.
• European Union. Since the 2009 amendment, the ePrivacy Directive's safeguards against unsolicited email also apply to SMS, MMS and similar messages²¹.
• United Kingdom. PECR allows texts to companies, but sole traders and some partnerships count as individuals and need consent or the soft opt-in²⁰.
• India. TRAI's 2018 regulations govern commercial messages; the February 2025 amendment brought most changes into force 30 days after publication and some after 60 days¹⁶, and TRAI amended them again in September 2026¹⁷.
• UAE. The e& consent management policy requires promotional sender IDs to carry an "AD-" prefix, alongside registered sender names and consent records¹⁸.
• Saudi Arabia. The CST has consulted on an anti-spam framework that would require consent before sending, an unsubscribe facility and accurate sender details¹⁹; check the rules in force with the CST.
• Platforms. WhatsApp's policy requires approved templates to start conversations⁵; Messenger and Instagram forbid promotions under message tags⁸. Store each opt-in in your CRM with its date, source and scope, and manage it with consent management.

• Consent that does not travel. A consent covers the sender and campaign it was given for¹⁵; an email opt-in is not automatically an SMS or WhatsApp opt-in. WhatsApp asks for the business name to be stated clearly at opt-in⁴.
• Template sprawl. Templates must be approved and categorised¹⁵; a marketing message filed as utility breaks the policy. Plan a small set of well-written templates.
• Over-messaging. Meta recommends separate opt-ins by message category precisely because unsolicited messages lead people to block a business⁴.
• Ignoring the window. Replies after 24 hours need a template on WhatsApp⁵ or an approved tag on Messenger and Instagram⁷.
• Prices that move. WhatsApp prices can change each quarter and its rules for utility replies changed in October 2026¹²; budget with headroom.
• One market's rules everywhere. India, the UAE, the US and the EU each have their own consent and registration regimes^13161821.

• Per-message billing widens. From 1 October 2026 WhatsApp charges for utility replies inside the customer service window².
• Encrypted RCS. End-to-end encryption between iPhone and Android is rolling out in beta¹².
• US consent rules in flux. The FCC's 2026 changes to how consent is revoked¹⁴.
• India keeps tightening. TRAI amended its commercial communications regulations again in September 2026¹⁷.
• Messaging as a revenue line for Meta. Meta told investors that paid messaging passed a $2 billion annual run-rate in late 2025²².

Choose messaging when speed and conversation matter: a question before a purchase, a reminder before an appointment, an update after an order. Pair it with email for longer messages, map where it sits in the touchpoints and journey, and keep the opt-ins in one place with your other first-party data. See the messaging discipline page and which mix for which objective.