SMS marketing: the complete guide

Your SMS contact list may be one of the smallest audiences you can reach directly. It is also one of the few where every message you send comes with an immediate cost.

That changes how you should approach the channel.

With email marketing, sending a poorly targeted campaign may primarily affect engagement and deliverability. With SMS marketing, you also pay for every unnecessary message. And when someone no longer wants to hear from you, opting out can take just a few seconds.

Yet SMS has a genuine advantage: immediacy. A well-timed text can reach customers when a message is still relevant, whether that's a delivery update, an appointment reminder, or an offer that is about to expire.

The challenge isn't simply getting people to open your messages. It's knowing who should receive an SMS, when they should receive it, and whether SMS is even the right channel.

To answer those questions, you need to understand more than campaign copywriting. You need to look at consent, costs, message types, automation, and the technology behind delivery.

What is SMS marketing and what does it include?

SMS marketing uses text messages to communicate directly with customers, typically through promotional campaigns or automated messages triggered by specific events.

These messages generally fall into two categories.

Promotional SMS Messages

Promotional SMS campaigns are designed to encourage a commercial action. They might announce a product launch, share an exclusive discount, promote an event, or encourage a customer to return.

For example:

MAISON B: Our autumn collection is here. Explore the new arrivals: [link]. Reply STOP to opt out.

Because these messages serve a marketing purpose, they are subject to applicable direct marketing and consent regulations.

In the European Union, prior consent is generally required for electronic direct marketing, although specific exceptions may apply, including certain communications to existing customers. Other markets have their own rules.

Transactional SMS Messages

Transactional SMS messages provide information related to an action, purchase, or service.

Examples include:

• Order confirmations and shipping notifications
• Delivery updates
• Appointment reminders
• One-time passwords and verification codes
• Important service notifications

Unlike promotional messages, genuinely transactional communications may not require marketing consent, although privacy, contractual, and other applicable obligations still apply.

The distinction matters because the same message can move from one category to another depending on its content.

An order confirmation that simply provides delivery information is transactional. Add a discount for the customer's next purchase, and you introduce a promotional purpose that may change the legal requirements.

Before combining marketing and service information in a single SMS, make sure you understand the rules that apply to your recipients.

For a closer look at triggers, templates, and delivery workflows, see our guide on how to set up effective transactional SMS.

How much does SMS marketing cost?

The economics of SMS marketing are relatively straightforward: you generally pay for the messages you send, rather than the number of contacts you store.

That makes SMS different from many email marketing pricing models, where costs are often linked to contact volume, subscription tiers, or sending allowances.

Imagine sending the same promotional message to 50,000 contacts.

If only a small proportion are genuinely interested in the offer, you still incur the cost of reaching the entire audience. Better segmentation could have reduced the number of messages without necessarily reducing the campaign's effectiveness.

This is why SMS marketing costs should be evaluated alongside targeting quality, not simply the price of sending one text.

What determines the cost of an SMS campaign?

Several factors influence your final SMS marketing bill.

Destination country. SMS rates vary by market, mobile network, and provider. International campaigns can involve substantially different costs depending on where recipients are located.

Message length and encoding. A standard SMS using GSM-7 encoding can contain up to 160 characters. Longer messages are divided into segments, with up to 153 characters per segment.

Characters outside the GSM-7 character set, including many emojis and certain punctuation marks, can trigger Unicode encoding. That reduces the limit to 70 characters for a single SMS or 67 characters per segment for longer messages.

A seemingly harmless emoji or punctuation change can therefore increase the number of billable segments.

Your SMS gateway provider. Providers differ in their rates, geographic coverage, and delivery arrangements.

Your marketing platform. Some SMS marketing platforms bundle delivery into their pricing. Others allow businesses to connect an external gateway and manage messaging costs separately.

Before choosing a tool, understand how these elements fit together. A low advertised price per SMS doesn't necessarily tell you what an international campaign will cost.

Why SMS segmentation matters more than sending volume

A large SMS list isn't particularly valuable if most recipients have no reason to respond.

Consider a retailer announcing that a popular product is back in stock.

Sending the notification to everyone who has ever purchased from the store would be expensive and potentially intrusive.

Sending it only to customers who expressed interest in that particular product creates a much more relevant interaction.

The same principle applies to renewal reminders, limited-time offers, and customer reactivation campaigns.

The goal isn't simply to send fewer SMS messages. It's to avoid paying for messages that have little reason to be sent.

And that makes segmentation a financial decision as much as a marketing one.

‍

Who actually sends your messages

Marketing platforms handle SMS one of two ways, and the difference lands on your invoice and in your compliance file.

Some SMS marketing software resell messaging. You buy credits at their rate and they handle delivery through carriers you never see or think about. Simple to start with, and you pay a margin on every message you ever send.

Others orchestrate, and you bring your own gateway. Positive User works this way. You hold the contract with an SMS provider and connect it, and the platform then handles content, targeting, journeys and reporting while the gateway does the actual delivering.

The honest version of the trade-off, since you should hear it from us rather than from a competitor: this is one more account to open before your first send, and because we do not run the delivery infrastructure, your delivery rate is your provider's responsibility rather than ours.

What you get back matters more in Europe than almost anywhere else. You negotiate your own per-message rate instead of paying a reseller's margin on top. You can pick a provider that already operates in your markets, which is the difference between being able to register a sender ID in Poland or Italy and discovering three weeks before launch that you cannot. And if the rates or the coverage stop working for you, you change provider without changing marketing platform.

What European law asks of you

Most SMS advice written in English is written for the United States, where the rules are built differently. If you send into Europe, four things hold everywhere.

• Explicit consent before any promotional SMS messages. Freely given, specific, informed. A pre-ticked box is not consent and has not been for years.
• A free opt-out in every marketing communications message, acted on immediately.
• A sender the recipient can identify from the message itself.
• A lawful basis and a documented retention period for the phone numbers you are holding.

Then every country adds its own layer on top. France restricts promotional SMS messages to defined daytime hours on weekdays and Saturdays and bans them on Sundays and public holidays. Germany, Italy, Spain and Poland each enforce their own way, and sender ID registration works differently in each.

If you send across markets, the SMS marketing software has to apply those rules itself. Leaving it to whoever happens to be scheduling that week does not survive a busy December, and it quietly makes a junior marketer your compliance control, which is not a position anybody applied for.

One more thing, and it is the first question your legal team will ask: where the phone numbers are stored. Run European phone numbers through a US-hosted platform and somebody eventually has to justify the transfer in writing.

Which SMS marketing messages to switch on, and in what order

Order matters more than copy here, because your first few text messages decide whether anybody sticks around for the rest.

SMS messages people are waiting for

Order confirmation, shipping notice, delivery window, appointment reminder, login code. The highest volume use of SMS marketing in Europe by a wide margin, the lowest opt-out risk, and in most jurisdictions no marketing consent required.

SMS marketing messages that are only useful right now

Back in stock on the thing somebody asked about. A webinar reminder two hours before. A sale closing tonight. Urgency is the one thing SMS marketing does better than every other marketing channel, so spend it on things that are actually urgent.

SMS marketing messages with an obvious rhythm

A welcome text after signup. A renewal reminder before a subscription lapses. A reorder nudge timed to how long the product really lasts. A birthday. These read as service rather than sales, because the timing makes sense to the person receiving them.

SMS campaigns for reactivation

Somebody who has not been back in a couple of weeks, or a win-back at 90 days.

Abandoned cart, last, and carefully

It works, and it is the single most promoted SMS use case online, mostly because the US direct-to-consumer playbook was written by platforms selling into that market. It is also the most intrusive message on this list. It fires within the hour, it makes plain that you were watching somebody browse, and in the EU it needs explicit marketing consent that plenty of SMS subscribers gave you for delivery updates and nothing else. Run it after everything above and expect a higher opt-out rate than anything else you send.

Writing to the constraint

Brand name first, so people know who you are from the notification preview. One offer. One shortened, trackable link. The opt-out at the end. Stay inside one segment unless the second genuinely earns its cost.

Most first drafts are twice as long as they need to be, and here the length has a price tag. Same SMS marketing message, before and after a real edit:

> Before. 191 characters, two billed segments.

Hello Sarah, we wanted to let you know that the item you asked us about at Maison B is now back in stock and available to order again on our website. Click here to view it before it sells out.

> After. 112 characters, one segment.

MAISON B: Sarah, the boots you wanted are back in stock. 3 pairs left: [link] STOP to opt out

Half the cost, and it reads better. Do that edit on every SMS campaign. And send yourself a test before publishing, because a broken link in a text message cannot be fixed after the fact and you paid for every one of them.

SMS marketing with Positive User

SMS marketing runs on the same contact record as email, WhatsApp, web push, mobile push, mobile wallet and live chat, with one set of consents across all of them.

One journey can change channel

Send the email, wait a day, check who clicked, then text only the people who did not and who opted in to SMS. Your SMS spend falls and your campaign reach rises at the same time, which is not a combination you get offered often. Across two separate tools the pattern is unusable, because you cannot reconcile the contact bases fast enough to trust what you are looking at.

Click tracking depends on the built-in link shortener

Worth knowing before somebody switches it off to save characters. Turn it off and the message still sends, still gets read, and records no click data whatsoever. It is the only engagement signal SMS marketing gives you, and a campaign without it is a campaign you cannot judge.

Delivery logs price each message individually

Every message appears with its status, its failure reason if it failed, and the price calculated for sending it. Put that next to the clicks tab and you have cost and response at the level of the individual message, which is the only honest way to judge an SMS program.

Numbers have to be in E.164 format

Country code, no spaces, as in +33600000000. Anything else fails at send. This stops more first SMS campaigns than any other single thing, and it always gets discovered on launch day.

What this looks like with real customers

An honest note before the numbers. We do not currently publish SMS-specific results. What follows measures email and automation, and it is here because the mechanism is the one this article argues for, not because these are SMS benchmarks wearing a disguise.

LG Electronics reports a 50% open rate and doubled revenue

Carrefour puts an 88% revenue increase.

Both got there through triggered, segmented messaging rather than volume. That is exactly how an SMS marketing strategy should be built, and it is the part that transfers.

How to judge an SMS marketing platform

Feature lists will not separate the candidates, because every vendor has every feature and every demo goes well. These six questions do separate them.

Put the answers side by side. A table built from your own answers beats a comparison published by any of the candidates, ours included.

Why Positive User

Your own gateway, your own rates

You keep the contract and the price you negotiated instead of paying a platform margin, and you can choose a provider that already works where your customers are.

One record, one consent state

SMS, email, WhatsApp, web push, mobile push, wallet and chat all read the same profile. An opt-out is recorded once and applies everywhere.

Cost and response at message level

Delivery logs show the price of each individual message alongside whether it arrived and who clicked it.

Data stored securely in Europe

Phone numbers and contact data are stored in Europe, in France and Germany.

Built visually, tested on a real journey

ourneys are built in a visual editor. The demo test worth insisting on: hand the keyboard to whoever will run this daily and ask them to build a two-channel journey while you watch.

Channel coverage and available gateways are on the Positive User SMS marketing page.

{{CTA-BLOG}}

Frequently asked questions

Before your first send

Two things to check, and neither of them is the copy.

Do the phone numbers in your database have documented marketing consent, separate from email consent? And is the first SMS message you plan to send one the recipient is actually expecting?

If both answers are yes, the channel starts earning in the first week. If either is no, that is the work, and it comes before anything you write.