SMS campaigns: 7 best practices to engage without overwhelming
7 min - 26 October 2026
A text arrives, the screen lights up and the message is read almost straight away. Few channels get this close to your customers. That is also what makes an SMS campaign tricky: one poorly targeted message, sent at the wrong time or once too often, and your customer replies STOP.
Between character limits and consent rules, a successful SMS campaign takes more than good copy. Here are seven best practices to make every message count without wearing out your customers, and to give SMS its proper place in your omnichannel marketing mix.
What is an SMS campaign?
An SMS campaign means sending a text message to a targeted group of contacts, as a one-off or through automation, to promote an offer or support customers along their journey. When the message is promotional, it is known as SMS marketing.
In the UK, these messages fall under the Privacy and Electronic Communications Regulations (PECR), enforced by the Information Commissioner’s Office (ICO). ICO guidance draws a clear line between direct marketing and service messages, which follow different rules:
Type of SMS | Purpose | Examples | Main rule |
| Marketing to individuals (SMS marketing) | Promote a product, a service or the brand | Sales, discount codes, new collection launch | Prior consent, or the “soft opt-in” for existing customers and similar products |
| Service message | Give customers information they need about an order, account or service | Order confirmation, delivery update, password reset | Outside the marketing rules, but UK GDPR still applies |
| Marketing to companies | Promote an offer to a business | Invitation to a trade event sent to a company phone | No consent or soft opt-in needed, but you must identify yourself and offer an opt-out. Sole traders count as individuals |
Watch out for hybrid messages: according to the ICO, a service message that includes promotional content counts as direct marketing, so the marketing rules apply. The same logic applies to transactional email: it exists first to inform the customer.
Why SMS is still a key mobile marketing channel
Between friends and family, texting is in steep decline. According to Ofcom, UK mobile users sent 4.61 billion SMS and MMS messages in the first quarter of 2026, down 21.3% on the same quarter a year earlier (Ofcom, Telecommunications Market Data Update). Personal conversations are moving to messaging apps and RCS.
For brands, though, SMS still offers a combination few channels can match:
- It reaches every phone, with no app to install and no internet connection needed.
- It doesn’t depend on notification permissions, unlike push.
- It suits short, time-sensitive messages: confirmation codes, appointment reminders, limited-time offers.
- It works as a fallback when a WhatsApp message or a notification hasn’t been opened.
SMS is therefore best treated as one part of your mobile marketing strategy, coordinated with email, push and WhatsApp.
7 best practices for successful SMS campaigns
These seven practices cover the full life of an SMS campaign, from targeting to follow-up. They apply to one-off sends and automated scenarios alike.
1. Target before you send
Sending an SMS to your entire database is expensive and wears out your customers. Before each send, define who has a genuine reason to receive it: purchase history, local store, last interaction. For an in-store offer, limit the send to customers who live near the shop or regularly pass by.
2. Pick the right moment
Texts are read quickly, so send them when your customer can act. Avoid early mornings, late evenings, Sundays and bank holidays. For messages triggered by an action, such as an abandoned basket or a booking, the send should closely follow the behaviour that prompted it.
3. Keep it short and watch your characters
A standard SMS holds 160 characters. Beyond that, the message is split into 153-character segments, each one billed. The pound sign (£) belongs to the standard SMS alphabet (GSM 7-bit), but the euro sign (€) counts as two characters, and a single emoji or non-standard character can switch the whole message to Unicode, cutting the limit to 70 characters (LOX24, SMS encoding).
Get straight to the point: the offer, the deadline, the action you expect and a short link. Actito includes a built-in SMS shortener powered by AI that trims your text to fit the limit, so you avoid paying for several messages.
4. Take care of the landing page
The link in your SMS opens on a smartphone, with only a few seconds of attention. The page needs to load fast, read well on a small screen and show the advertised offer. A customer who clicks on a promotion and can’t find it on the mobile site loses trust, and often abandons the purchase.
5. Control the frequency
Send too many texts and the STOP replies soon follow. Set a maximum marketing pressure per customer across all channels: a customer who has already received an email and a push notification about an offer can do without an SMS about the same offer on the same day. Let customers choose how often they hear from you and what type of messages they receive.
6. Respect consent
Rules applicable in the UK.
Under PECR, you need prior consent to send marketing texts to individuals, and that consent must name your organisation and specifically cover text messages. The “soft opt-in” is the exception: you can text your own customers about your similar products or services if you collected their number yourself during a sale or negotiation, offered them a chance to opt out at that point, and offer it again in every message (ICO).
Every marketing text must include a simple opt-out that costs nothing beyond the price of sending the reply, typically by texting STOP. The ICO recommends keeping a “do not contact” list so you never message people who have opted out. To secure your data collection, follow the rules for valid consent.
7. Plan a multichannel follow-up
SMS works very well as a relay for another channel. Take a limited offer sent by WhatsApp: if the customer hasn’t opened it within 24 hours, an SMS reminder goes out automatically. With Actito, a marketing scenario can be paused until the WhatsApp campaign is opened, then redirect the contact to SMS if no action is detected.
Measuring the performance of your SMS campaigns
SMS open rates stay out of sight: unlike email, no tracking pixel reports when a message is read. Performance is measured through five indicators instead.
Indicator | What it measures | What it’s for |
| Delivery rate | Share of texts actually received | Spot invalid numbers and clean your database |
| Click-through rate | Share of recipients who click the link | Gauge interest in the offer and the message |
| Conversion rate | Share of recipients who buy or book | Measure the campaign’s business impact |
| Opt-out rate | Share of STOP replies | Detect excessive marketing pressure |
| Cost per conversion | Total campaign cost divided by the number of conversions | Compare SMS with other channels |
Test one variable at a time (timing, wording, offer) with A/B testing, then track these figures over time using the marketing KPIs that really matter.
Conclusion: make every SMS campaign a message customers welcome
A successful SMS campaign comes down to a few precise choices: tight targeting, short copy, good timing and consent in order. Coordinated with email, push and WhatsApp, SMS becomes a reliable relay for your entire mobile strategy.