SMS is the highest-leverage channel in the webinar reminder layer. It’s also the channel with the most compliance friction. Here’s the plain-English version of what you need to know.
The three layers of compliance
1. TCPA (federal)
The Telephone Consumer Protection Act is the federal framework for marketing SMS in the U.S. The short version:
- You need express written consent before sending marketing SMS
- The opt-in language must clearly state messages will be sent
- The consent must be standalone (not bundled with a Terms acceptance)
- The contact must be able to opt out at any time via STOP
2. A2P 10DLC (carrier-level)
10DLC is the U.S. carrier registration regime for application-to-person SMS. To send SMS from a 10-digit long code (a regular phone number) to U.S. carriers without rate-limiting, you must register your brand and your campaign(s).
- Registration is done through your SMS provider (Twilio, GHL, etc.)
- Brand verification typically takes 1–3 business days
- Campaign approval typically takes 3–7 business days
- Without 10DLC registration, your messages may be filtered or blocked
3. State laws
Some states have stricter rules than the federal baseline. Florida (FTSA) and Washington (CEMA) are the two most common to trip operators up. Most operators choose to follow the strictest applicable rules across all states for consistency.
What “express written consent” actually looks like
On your webinar opt-in form, you need a clear consent line near the submit button. Example:
“By registering, I agree to receive event reminders and follow-up messages via email and SMS from [Brand Name]. Message frequency varies. Message and data rates may apply. Reply STOP to opt out.”
The line must be visible — not buried in a Terms of Service link. The submit button text should make it clear that submitting is the consent action.
The “STOP” keyword
Every SMS message must support a STOP-style opt-out. The standard set of keywords your provider should auto-handle:
- STOP / STOPALL / UNSUBSCRIBE / CANCEL / END / QUIT — auto-opt-out
- HELP / INFO — returns brand contact info
- START / YES / UNSTOP — re-subscribe
Your SMS provider (GHL, Twilio) handles these automatically. Don’t try to handle them in your workflows.
The webinar-specific compliance moves
- Cap SMS at ~5 touches per webinar registration (T-24h, T-1h, T-15m, T-5m, T+30m)
- Suppress SMS for contacts who’ve already attended
- Stop all SMS in the post-webinar branch if the contact opts out
- Don’t send marketing SMS between 9pm and 8am in the contact’s timezone
What the snapshot does
- The 7-touch cadence is tuned to stay inside reasonable SMS volume per registration
- All STOP / HELP / START keywords are handled automatically
- Behavioral skip-logic suppresses SMS to already-attended contacts
- Per-channel opt-out is respected end-to-end
- A2P 10DLC registration is walked through during the install call
Get the snapshot → — compliant SMS reminder layer pre-built.