Bulk SMS Marketing: How to Send at Scale

Sending a text to 50 customers is easy. Sending one to 50,000 is a different job. At that volume, a formatting error in your contact list means thousands of failed messages, one extra character can double your bill, and every message that annoys a recipient becomes thousands of opt-outs.

So what actually changes when you move from a few texts to bulk SMS marketing? Mostly the preparation: a clean list, a registered sender, careful message length, and a sending plan that ramps up instead of firing everything at once.

The information in this article was last updated on November 6, 2026.

Table of Contents

• What is bulk SMS marketing?
• Before you send: get permission and register your sender
• How to send bulk SMS in 7 steps
• How much does bulk SMS cost?
• Metrics to watch at scale
• How to send bulk SMS with Brevo
• Plan the send, not just the message

What is bulk SMS marketing?

Bulk SMS marketing means sending the same text message, often personalized, to a large group of contacts at once: a promotion, an event reminder, a back-in-stock alert, or a store announcement. Messages go out through an SMS platform rather than a phone, so you can segment recipients, schedule sends, handle opt-outs, and track results.

It's different from a group text. In a group text, everyone sees each other's replies. In a bulk SMS campaign, each person receives the message individually, and replies come back only to you. Bulk campaigns are different from automated texts, which go to one person at a time when they do something, like placing an order. For those, see this guide to sending automated texts. If you're new to the channel, this guide to SMS marketing covers the basics.

Before you send: get permission and register your sender

A compliance gap that affects one text affects every text in a bulk send. Two things need to be in place first.

Consent for every contact. Text only people who agreed to receive marketing texts from you, and keep a record of how they opted in. Under rules the FCC adopted in December 2023, Do-Not-Call list protections apply to text messages, so marketing texts to numbers on the National Do Not Call Registry without permission carry legal risk. Never buy or rent phone lists. For a clean way to collect consent, see this guide to double opt-in.

A registered sender for US contacts. Texting US contacts requires a registered sender number. With Brevo, for example, texting US contacts requires registering a toll-free number, and the review "can take up to 4-6 weeks." The form asks for your expected monthly volume, use cases, sample messages, and a screenshot of your opt-in process, so prepare those before you plan a launch date.

This article isn't legal advice. Check the rules that apply to your business and the states you text.

How to send bulk SMS in 7 steps

1. Clean and format your contact list

Most failed bulk sends start with the list. Before importing:

• Format every number with the country code. Brevo's help center says SMS numbers must be stored "including the + sign and the country code", such as +1 for the US.
• Remove duplicates. In Brevo, for example, each phone number can belong to only one contact.
• Remove landlines. According to Brevo's SMS deliverability guide, texts to landline numbers result in a soft bounce.
• Keep the opt-in source and date as contact attributes, so you can show consent if asked.

2. Segment instead of blasting everyone

Bulk doesn't have to mean identical. Split your list by what people bought, where they live, or how recently they engaged, and send each group a message that fits. A store opening only matters to people nearby, and a restock alert only to people who looked at that product. Fewer irrelevant texts also means fewer opt-outs. These customer segmentation examples give you ideas for groups to start with.

3. Write a message that fits in one SMS

A standard SMS holds 160 characters. Longer messages are split into several parts, and each part is billed as a separate SMS. Special characters and emojis reduce the limit to 70 characters per SMS, according to Brevo's help center. Every marketing text should also:

• Start with your business name, so people know who's texting.
• Make one clear offer or point, with a deadline if there is one.
• Use one link on your own domain. Brevo's country guidelines prohibit public URL shortener domains such as bit.ly for US texts.
• End with an opt-out, such as "Reply STOP to opt out."

Personalization, such as the contact's first name or nearest store, helps a bulk message feel less like a broadcast. Check the final length with the longest name in your list, not the shortest.

4. Send a test to real phones

Send the message to a few test numbers on different carriers and phone models. Check that the name and link display correctly, the link opens the right page on mobile, and the message arrives as a single SMS.

5. Schedule for the recipient's local time

With a national list, "10 a.m." means different times for different contacts. Brevo's guidelines list 8 a.m. to 9 p.m. local time for US marketing texts, and 8 a.m. to 8 p.m. in Florida, Oklahoma, and Washington. Segment by time zone if needed, and schedule each group within its allowed hours.

6. Ramp up volume instead of sending everything at once

Rather than sending to your whole list at once, start with your most engaged contacts and increase volume over several days. Brevo's SMS campaign guide recommends starting with about 3,000 messages per day and increasing by 30% each day when you send in batches.

7. Track results and clean as you go

After each campaign, review delivery rate, clicks, replies, and opt-outs, and remove numbers that bounce. Brevo also recommends removing contacts who haven't engaged with any campaign for a long time, and sending SMS campaigns at least once a month so your audience keeps recognizing you.

How much does bulk SMS cost?

SMS is usually billed per message part, not per contact. That makes message length the biggest lever on cost.

Here's an example using Brevo's starting rate of $0.0109 per message credit in the US. Actual rates vary by country and volume.

Trimming a message to fit in one SMS, and leaving emojis out, can halve the cost of a send. Sending to an engaged segment instead of the full list reduces it further.

Metrics to watch at scale

• Delivery rate: The share of messages that reached a phone. A drop often points to bad numbers or carrier filtering.
• Click-through rate: Clicks on your link divided by delivered messages.
• Opt-out rate: STOP replies divided by delivered messages. A spike after a campaign usually means the message wasn't relevant to that segment or you're sending too often.
• Replies: At scale, someone needs to read them. Questions, complaints, and "wrong number" replies all need a process.
• Revenue or conversions per campaign: Track them with a dedicated link or code so you can compare SMS with your other channels.

How to send bulk SMS with Brevo

Brevo sends SMS campaigns from the same platform as your email campaigns, contact database, and automations:

• Import and segment contacts: Store phone numbers in the SMS attribute, choose the lists or segments to send to, and check "Don't send to unengaged contacts" to leave out people who no longer interact with your messages. You can refine the audience further with exclusions and filters.
• Write and personalize: The editor shows the character count and the number of SMS the message will use, and you can add contact attributes such as {{contact.FIRSTNAME}}.
• Stay compliant: For US numbers, the "Manage US compliance" option adds your organization prefix and opt-out instructions, and STOP replies automatically unsubscribe and blocklist the contact.
• Send in batches: Batch sending is available on the Professional and Enterprise plans.
• Handle replies: Brevo supports two-way SMS. Replies arrive in the Conversations inbox, and for US and Canadian numbers you can answer by SMS.

SMS is available on every Brevo plan, including Free, with pay-as-you-go credits that start at $0.0109 per message credit in the US. For other options, see this comparison of SMS marketing software, and for the email side of large sends, this guide to bulk email campaigns.

Plan the send, not just the message

Bulk SMS marketing works at scale when the groundwork is in place: opted-in contacts, a registered number, numbers formatted with country codes, messages that fit in one SMS, and a send that ramps up and respects local hours. After each campaign, watch delivery, clicks, and opt-outs, and keep cleaning your list.

Brevo lets you send SMS campaigns to segmented lists, personalize each message, and follow up by email from the same platform. Explore Brevo's SMS marketing features.

Numa des Borderies is Content Director at Brevo, specializing in email marketing, marketing automation, CRM, and Customer Data Platforms. With 10+ years of digital marketing experience, he creates comprehensive guides by testing and analyzing marketing tools to provide practical, actionable insights. At Brevo, he helps professionals navigate complex marketing topics: email deliverability, automation workflows, CRM/CDP strategies, and AI adoption. He holds a Master’s degree in philosophy and is interested in how humanities contribute to marketing.