SMS is the highest-response-rate channel for transactional surveys in service businesses. It also comes with the strictest compliance constraints in CX. This guide covers what makes SMS surveys work, what trips most teams up, and what to look for in an SMS-capable platform.
Why SMS outperforms email for service businesses
- Open rate. SMS open rates are typically above 95%; email runs 20-30%.
- Time to response. Most SMS responses arrive within 90 minutes.
- Service context. The technician just left or the ticket just closed. SMS catches the moment.
- Mobile-first audiences. Tenants, homeowners, and field-service customers often check SMS more than email.
What to look for in SMS survey software
STOP suffix, opt-out tracking, quiet hours, and one-click unsubscribe per channel.
Sends suppressed during local quiet hours based on contact timezone.
Cross-channel cooldowns so SMS and email don't double-tap the same person.
A short, single-use link that authenticates the response without forcing a login.
Real-time delivery status so you can detect carrier rejections fast.
SMS shouldn't be a bolt-on with separate contact lists.
The 306-character reality
A single SMS segment is 160 characters. AwareCX caps total outbound at 306 characters (two segments) to keep cost and deliverability predictable. That total includes:
- Your custom message body
- The survey response link
- Your company identifier
- The required "Reply STOP to opt out" suffix
Practically, keep your message body under 120 characters and the rest fits comfortably.
Compliance essentials
- Consent. Track express consent at the contact level; B2B is more flexible but consent is still the norm.
- STOP / HELP. Honor STOP immediately; HELP should return a brief description and contact info.
- Quiet hours. No sends during the recipient's local 8pm-8am window.
- Identification. Every message includes the sending company's name.
- One-click unsubscribe. Per RFC 8058 for email, and STOP for SMS.
AwareCX enforces all of the above automatically. The deliverability guide has the full reference.
When NOT to use SMS
- Long-form relationship surveys. The constraints push you toward something email-shaped anyway.
- Audiences without phone numbers on file. SMS coverage depends on data hygiene; clean your contacts first.
- Geographies with restrictive SMS rules. Some EU markets have stricter B2C SMS regulation.
- Cold outreach. SMS surveys assume an existing customer relationship.