SMS has the highest open rate of any outreach channel - most messages are read within minutes. But in B2B, that immediacy is a double-edged knife. A cold SMS from an unknown sender is more likely to get a block than a reply. Used correctly - as a follow-up touch after earlier engagement, not as a cold first contact - SMS is one of the most underused channels in B2B outreach and one of the few that can still generate genuine surprise-and-delight reactions from prospects.
Does SMS Actually Work for B2B?
The numbers on SMS open rates are real: most text messages are opened within three minutes of receipt, and overall open rates are well above 90%. These statistics are often cited as the reason to add SMS to B2B outreach. But they obscure an important nuance: open rate and response rate are very different things, and the response dynamic for cold SMS is much less favorable than for warm SMS.
A cold SMS from an unknown number asking about a business tool gets ignored or blocked far more often than it gets a reply. Prospects are accustomed to consumer SMS marketing and have trained reflexes for dismissing unsolicited texts. The high open rate reflects curiosity about who sent the message, not a predisposition to engage with what it says.
What changes the equation is context. A prospect who has seen your name on LinkedIn, opened two of your emails, and perhaps accepted your connection request already has a mental model of you. When a brief SMS arrives from that same sender, it is processed differently - not as a cold solicitation but as another touch from someone they have been following up on.
In our experience, SMS touches added as the fourth or fifth step in a sequence - not as the first or second - consistently add meaningful lift to overall sequence reply rates. The lift is highest in geographies where SMS is a normal professional communication channel: North America, Australia, and parts of Latin America. In Europe and Asia where WhatsApp is the preferred short-message platform, WhatsApp as a follow-up channel often outperforms traditional SMS for the same use case.
See our guide on WhatsApp B2B outreach for the WhatsApp-specific playbook, and our piece on Telegram B2B outreach for a look at the third major short-message channel.
When SMS Makes Sense in a B2B Sequence
SMS belongs at specific moments in a sequence, not as a default channel at every stage. The scenarios where it consistently adds value:
As a mid-sequence follow-up after email silence. The prospect opened your first two emails but did not reply. They are aware of you but have not engaged. A brief SMS referencing your emails - "Hi [Name], I sent a couple of notes over email last week. Is this still relevant for your team?" - provides a different channel nudge that sometimes gets the reply the emails could not.
As a channel switch when email is not reaching the inbox. If your emails are landing in spam or promotional folders, SMS bypasses the inbox entirely and reaches the prospect directly. This is particularly useful when you have reason to believe the contact is actively looking for a solution but your emails are not getting through.
For time-sensitive follow-up after a trigger event. If a prospect just got a new funding round, published a post about a pain you solve, or just started a new role where your solution is relevant, a brief SMS the same day - while the trigger is still fresh - can generate a response that an email sent four days later would not.
As a final touch in a sequence before closing the loop. The break-up message in a sequence often works well via SMS because the brevity of the channel matches the lightness of tone you want for a break-up message. "Hi [Name] - I'll stop following up after this. If the timing ever changes, I'm easy to find. Take care." This kind of message, sent via SMS, often generates warm replies from prospects who feel slightly guilty about not responding to your emails.
What SMS is not suited for: cold first touch, long sales pitches, demos, or any message that requires the prospect to click a link and engage with a website. The attention window on SMS is seconds, not minutes. If your message cannot be read and processed in 10 seconds, it does not belong in SMS.
Building a Compliant B2B SMS Program
SMS compliance requirements vary significantly by country and context. Getting this wrong can result in fines, blocked numbers, and reputational damage. The basics every B2B SMS program needs:
US compliance (TCPA and CTIA guidelines): The Telephone Consumer Protection Act has specific requirements for SMS marketing. For B2B SMS outreach specifically, the rules are somewhat more permissive than for consumer SMS, particularly for manually dialed or individually sent messages that are not sent via an automated telephone dialing system (ATDS). However, using SMS platforms that send via bulk automation changes the analysis. Always identify yourself in the first message, include a clear opt-out mechanism ("Reply STOP to opt out"), and honor opt-outs immediately and permanently.
European compliance (GDPR): In the EU and UK, SMS marketing to individuals generally requires explicit consent. B2B SMS to company phone numbers is subject to different rules in some jurisdictions, but the safest approach is to only SMS contacts who have given consent or where there is a clear legitimate interest basis that you can document. The regulatory environment is strict and enforcement is active.
Canada (CASL): Canada's Anti-Spam Legislation covers SMS commercial messages and generally requires express consent. B2B implied consent provisions exist but are narrow. Getting legal guidance before running SMS outreach into Canada is advisable.
Practical minimum requirements for any B2B SMS program regardless of geography:
- Always identify who you are in the first message to an unknown contact.
- Always provide a clear way to opt out and honor all opt-out requests within 24 hours, permanently.
- Never send SMS to contacts who have previously requested to stop receiving messages from you.
- Keep records of opt-in and opt-out events for every contact.
- Do not send messages outside business hours in the prospect's timezone.
SMS Copy That Converts
Writing good B2B SMS copy requires a different mindset than email. The constraints are real: you have roughly 160 characters for a single SMS message (longer messages are split into multiple parts and often look awkward), you have no subject line to warm up the reader, and you have no formatting to guide the eye. Every word has to work.
The core framework for B2B SMS follow-up messages:
- Identify yourself immediately: "Hi [Name], this is [Your Name] from [Company]." Full stop. Do not assume they saved your number or remember you from email.
- Reference previous context: "I sent a couple of notes about [topic] last week." This reminds them why you are texting and signals that this is a follow-up, not a cold solicitation.
- Ask one direct question: "Is this still relevant for your team?" or "Would a quick 15-minute call be worth it?" One question only. The goal is a reply, not a conversion.
- No links in cold follow-up SMS: Links in SMS from unknown numbers trigger spam filters on many carriers and look suspicious to recipients. Save links for follow-up messages after a reply has been received.
Example sequence of SMS messages that work in practice:
Touch 4 of a 6-touch sequence (after 2 emails and 1 LinkedIn message):
"Hi [Name], [Your Name] from [Company] - I reached out last week about [1-line value prop]. Any thoughts? Happy to keep it brief."
Final touch (break-up message):
"Hi [Name], [Your Name] - I'll leave it here. If [pain point] becomes a priority later, feel free to reach back out. All the best."
Keep all SMS messages under 160 characters where possible. Test your character count before sending. A message that splits into two SMS parts often loses the second half to inattention.
Integrating SMS Into Your Multi-Channel Stack
The technical side of adding SMS to a multi-channel outreach sequence has gotten simpler as outreach platforms have expanded their channel support. What used to require separate SMS tools, Zapier integrations, and manual suppression logic can now be handled natively by platforms that support multi-channel sequences.
Key integration requirements for a B2B SMS program:
Phone number sourcing and verification. Mobile numbers for B2B contacts are harder to source than email addresses and are less reliably available in standard prospecting databases. Apollo, Cognism, and Kaspr are among the better sources for verified direct mobile numbers. Always verify numbers before adding them to an SMS sequence - sending to landlines or disconnected numbers generates carrier complaints and can get your sending number flagged.
Suppression sync across channels. If a prospect replies to an email asking to be removed from your list, they must also be removed from any active SMS sequence. And vice versa. Cross-channel suppression is a compliance requirement and a basic courtesy. Make sure your multi-channel platform handles this automatically - do not rely on manual suppression across systems.
Opt-out handling. Configure automatic handling of "STOP," "Unsubscribe," "Remove me," and similar opt-out responses. Every compliant SMS platform does this by default, but verify it is configured correctly before you send at scale.
Sending number reputation. SMS sending numbers - whether short codes, long codes (standard 10-digit numbers), or toll-free numbers - build and lose reputation with carriers over time, similarly to email sending domains. High complaint rates get numbers flagged. Using a shared short code (one number used by many senders) means another sender's bad behavior can affect your delivery. Where possible, use dedicated long codes or dedicated short codes for B2B outreach.
For a complete picture of how SMS fits alongside WhatsApp, email, and LinkedIn in an integrated outreach sequence, see our guide on multi-channel outreach.
FAQ
Is it legal to send SMS marketing to B2B contacts?
It depends on the country and the specific method of sending. In the US, B2B SMS sent to business phone numbers using individually crafted messages (not bulk ATDS sending) has more legal flexibility than consumer SMS. In the EU and UK, GDPR requires a valid legal basis for processing personal data including mobile numbers. Always identify yourself, always provide opt-out instructions, and always honor opt-outs immediately. For specific legal guidance in your jurisdiction, consult a privacy law professional.
What is the best time to send B2B SMS messages?
Business hours in the prospect's local timezone. Tuesday through Thursday between 9am and 5pm local time consistently outperform other windows. Avoid early mornings before 8am, evenings after 7pm, weekends, and public holidays. Automated scheduling tools can handle timezone optimization automatically if you have the prospect's location data.
Should I use a dedicated number or a shared short code for B2B SMS?
Dedicated long codes (standard 10-digit numbers) are generally the best option for B2B outreach. They look personal - like a message from a real person's phone - rather than obviously automated. Shared short codes save money but expose your sending reputation to other senders on the same code. Dedicated short codes are an option for high-volume senders but require additional carrier registration.
How many SMS messages should I send per prospect in a sequence?
One or two maximum, spaced by at least five to seven days. SMS is a high-interruption channel and overuse damages your reputation and generates complaints. A single well-timed SMS touch at the midpoint of your sequence and potentially one final break-up SMS is the right balance for most B2B outreach contexts.
What reply rate should I expect from B2B SMS outreach?
In our experience, B2B SMS touches added to an established multi-step sequence generate reply rates of 5-15% on the SMS touch itself, with the majority of replies being either a "not interested" or a genuine opening for conversation. Cold SMS without prior touchpoints typically generates much lower reply rates and higher block rates. The channel performs best as a mid-sequence or end-of-sequence touch, not as a standalone outreach method.