SMS_NO_OPT_OUT_LANGUAGE
Category: sms · Severity: warning (advisory) · Channel: SMS
The rendered SMS body contains none of the standard opt-out phrasings. A2P and TCPA guidance expects recurring marketing SMS to carry clear opt-out instructions.
What it means
Synapse Inspect scans the rendered message (after NLT expressions resolve) for a recognized opt-out instruction. If none is present, this advisory finding fires.
The check recognizes any of these phrasings (case-insensitive):
| Phrasing | Match rule |
|---|---|
reply stop | substring |
text stop | substring |
opt out | substring |
opt-out | substring |
STOP | whole word (so "stopwatch" and "nonstop" do not count) |
unsubscribe | word start (matches "unsubscribe" and "unsubscribed") |
This is an advisory finding. It is a warning and never blocks a send — an operator may legitimately carry the opt-out language elsewhere (for example, in a prior message in the conversation, or through a separate compliant channel).
Why it matters
Recurring marketing SMS in the US is governed by A2P 10DLC registration and TCPA. Recipients must have a clear, easy way to stop messages. Carriers can filter or block traffic from senders that don't honor opt-out expectations, and missing opt-out language is a common cause of deliverability and compliance problems.
Synapse always honors the standard STOP keyword at the platform level regardless of message text — this finding is about the visible instruction to the recipient, which A2P guidance expects.
How to fix it
- Add a standard opt-out phrase to the message body, such as:
Reply STOP to unsubscribe.
- Or confirm the opt-out instruction is delivered another way — for example, it was included in the opening message of the conversation — and snooze this finding.
Opt-out language also costs segments. Keep it short (Reply STOP to opt out.) and watch the segment count after adding it.
Related
- SMS quality checks — the full SMS Inspect guide
- SMS API reference