SMS marketing: the basics, and why consent comes first

The short answer

SMS marketing means sending text messages to people who have agreed to hear from you. Collect clear consent, say who you are, keep each message short and useful, make opting out simple and honour it at once. Rules differ by country, so check them with a qualified lawyer before sending anything.

What SMS is good for

SMS means short text messages sent to a phone number. They are seen quickly and need no app or internet account, so they suit time-sensitive and practical messages. They suit a few jobs well.

• Appointment and booking reminders.
• Delivery and order updates the customer expects.
• Short notices, such as a change of opening hours.
• Occasional offers, only to people who agreed to receive them.

They are a poor fit for long explanations, images-heavy content or frequent promotion. For those, email or a messaging app is better. Compare the options in WhatsApp Business basics and email automation basics.

Consent: the foundation

The central rule is that people should agree to receive your messages before you send them. Good practice goes further than a tick buried in small print.

• Ask separately. Do not hide text-message consent inside general terms.
• Say what you will send and how often, in plain words.
• Say who is sending, so the person knows it is you.
• Keep a record of when and how each person agreed.
• Do not buy lists of phone numbers or scrape them.
• Do not assume that giving a number for a delivery means agreeing to promotions.

Rules about text-message marketing vary a great deal between countries and sometimes within them, and they cover things like consent wording, sending times, sender identification and records. This guide gives general good practice only. Ask a qualified lawyer what applies in each place you send to.

Keep a record that you could show if asked: the wording the person saw, the date, the number and how they signed up. Do not rely on memory or on a screenshot saved on one person's laptop. Store the record with the contact so that anyone sending a campaign can see who has agreed and to what.

Review the list regularly. Remove numbers that bounce, clear out people who have not engaged for a long time and re-ask where you are unsure. A clean list is cheaper to run and safer to use.

Collecting numbers the right way

Use clear sign-up points: a form on your website, a tick box at checkout that is not pre-ticked, a sign-up at the till, or a booking form with a separate option. Put a short sentence beside the box, such as what the messages will be and how to stop them. Add a link to your privacy page.

Consider a confirmation message after sign-up so you know the number is correct and the person really wants it. Store numbers securely, collect only what you need and delete numbers when people leave or ask you to. The more you treat a phone number as personal, the fewer problems you will meet. Your CRM or email tool may be a safer place to record consent than a spreadsheet.

The habits in email list building carry over: ask openly, offer something worth having and never add people quietly. Once you have a list, grouping people by what they asked for, as in email segmentation, keeps messages relevant.

Writing a text that people welcome

Space is short, so every word counts. A good message identifies you, gives one useful piece of information, offers one next step and tells people how to stop.

The names above are examples only. Avoid capital letters, repeated punctuation and misleading urgency. Do not put sensitive details in a text, such as health or financial information, since a phone screen can be seen by others. Use a link you control and check that it works on a phone.

Think about the customer's day. A reminder that arrives the evening before an appointment helps. The same reminder sent three times does not. A delivery update at the moment a parcel is nearby helps. A sales message in the same minute does not. Match each text to a need the customer has at that moment, and leave promotions for a separate, clearly consented list.

Always read the message aloud before sending. If it sounds like something you would not say to a customer at the till, rewrite it.

Timing, frequency and opt-outs

Think about when a message lands. Do not send during hours when people are likely to be asleep, and think about the time zone of each recipient. Keep to the frequency you promised at sign-up, and send fewer rather than more. A short gap between messages makes a business seem pushy.

Make opting out easy and instant. State how to stop in the message or in regular reminders, and process requests straight away, not at the next campaign. Do not argue with someone who leaves. Keep a suppression list so a number that opted out is never added again by accident. Treat complaints seriously and look into the cause.

Choosing a provider and sender details

Most small businesses send through a messaging service rather than from their own phone. When comparing services, ask about delivery to the countries you serve, how sender names or numbers are registered, tools for managing opt-outs, reporting and integration with your other systems. Some countries require sender registration or approval before business texts can be sent, and these rules change, so check the current requirements and your provider's documentation.

Test with a small group first, including numbers on different networks and in different countries, and check how the message looks.

Plan for mistakes. Decide in advance who may send, who checks, and what you do if the wrong message goes to the wrong group. Keep a correction message ready, apologise briefly and do not send a second promotional text straight after. A scheduled send gives you time to catch an error, so check the preview and the recipient group before you confirm.

If you work with a third party, check how they store and use the numbers, and put the arrangement in writing.

Measure, then decide

Look at delivery, replies, opt-outs and the actions you wanted, such as bookings kept or orders placed. A sudden rise in opt-outs is a message about your content or frequency. Tag your links to see what comes from texts, as in the UTM guide, and compare the cost of a result with what a customer is worth, as in customer lifetime value explained.

If SMS is not helping, stop it. A smaller list of willing people beats a larger list of annoyed ones. Customers who pass your name on can be encouraged in a referral programme instead. If you need help planning messaging across channels, see our digital marketing service.

Related guides

• Digital marketing
• WhatsApp Business for Customer Communication: Basics
• Customer Lifetime Value Explained
• Youtube marketing basics for small business
• Referral marketing for small business
• Retargeting explained for small business

Questions and answers

Do I need permission to send marketing texts?

Good practice is to get clear consent before sending marketing texts, and many countries require it. Rules differ, so ask a qualified lawyer about the places you send to.

Can I text customers who gave me their number for an order?

Not necessarily for promotions. A number given for delivery may only cover delivery messages. Ask separately for marketing.

How often should I send text messages?

Less than you think. Tell people at sign-up what to expect, keep to it and lower the frequency if opt-outs rise.

How do I handle opt-outs?

Make stopping simple, act at once and keep a list of numbers that must not be messaged again.

Is SMS better than email?

They do different jobs. Text suits short, time-sensitive messages. Email suits longer content. Many businesses use both, with consent for each.