Part of our guide: What is the best marketing software for a small business in the UK?.
Written by Dan Sagar, FoundationsAI. Updated October 2026.
To use SMS marketing without annoying customers, only text people who've agreed to it or who are existing customers under the soft opt-in, and send marketing texts rarely (a couple a month at most). Make every text useful, send it at a sensible time and always say who you are and how to opt out. Most people don't mind texts from a business they know. They mind texts that are frequent, irrelevant or at 10pm.
Service texts vs marketing texts
| Service texts | Marketing texts |
|---|---|
| Appointment reminders, booking confirmations, "on my way" messages, replies to enquiries | Offers, promotions, seasonal reminders, newsletters |
| Fine to send, because they're about something the customer has asked for | Need consent, or the soft opt-in for existing customers |
| Can be sent as often as the job needs | Keep to a couple a month at most |
Most of the value for a service business is in the service texts. They're also the ones customers thank you for.
The UK rules
This isn't legal advice, but the basics are:
- You can send marketing texts to individuals who have agreed to receive them.
- You can also text existing customers, and people who asked you for a price, about your own similar services under the "soft opt-in", as long as you gave them a chance to opt out when you took their details.
- Every marketing text must say who it's from and give an easy way to opt out, such as "Reply STOP to opt out". Remove anyone who opts out straight away.
- Sole traders and most partnerships count as individuals.
- Never text a bought-in list.
The ICO's guidance has the detail.
When to send
- Weekdays between about 9am and 7pm for marketing texts.
- Avoid early mornings, late evenings and Sundays, unless it's something they're expecting, like a change to tomorrow's booking.
- Match the season. A boiler service reminder in September lands better than one in June.
Good texts vs annoying texts
| Annoying | Welcome |
|---|---|
| "SALE!!! 20% off all services this week only. Book now!" | "Hi Mark, it's Dan from Smith Heating. Your boiler service is due next month. Reply YES and I'll book you in. Reply STOP to opt out." |
| The same offer to every customer, every week | A reminder that matches what they've had done before |
| A text at 9.30pm | A text at 11am on a Tuesday |
Make each text count
- Use their name and mention what they had done or asked about.
- Say who you are in the first few words.
- Give one clear next step, like "Reply YES to book".
- Keep it short. One text is up to 160 characters. Longer messages are split and cost more.
What it costs
On FoundationsAI, a text to a UK mobile costs about 6p. Sending one text to 500 customers costs about £30. See the full cost breakdown.
Common questions
How often can I send marketing texts?
There's no legal limit, but a couple a month at most keeps most people happy. Service texts like reminders don't count towards that.
Do I need consent to send appointment reminders?
Reminders about a booking the customer made are service messages, not marketing, so they're fine to send.
Can I text people who asked for a quote but didn't book?
Usually yes, about your own similar services, under the soft opt-in, as long as you gave them a chance to opt out and include an opt-out in every text.
What's the best day to send a marketing text?
Weekdays during the day. Test a couple of different times and see which gets more replies.
Want it set up properly?
Book a 45-minute demo and we'll show you reminders, follow-ups and opt-outs all handled automatically on a live account.