Auto-reply messages must be 20–320 characters
The requirementstatement
The opt-in, opt-out and HELP reply messages must each be 20–320 characters.
- Severityseverity
- HighHIGHRejected by at least one carrier or provider, and a common cause of failure at the rest.
- When it bitesphase
- Gates approvalapprovalGet this wrong and the brand or campaign is refused at registration.
- What is checkedobject
- campaign.help_message + optin_message + optout_message
- Where it liveslayer
- CampaignCAMPAIGN
- How Ekas settles itdetectability
- DeterministicDETERMINISTIC
- Settled in code from the values you submitted. No model involved, no judgement call, same answer every time.
- What the fix involvesfailureClass
- Fix the fieldRETRY_FIELD
- A better value in the form fixes it. Ekas can rewrite it and re-check.
- Who requires itauthorities
- TwilioBandwidth
- When it appliesapplicabilityText
- Applies to every 10DLC registration.
Why this rule existsrationale
Auto-replies must fit the carrier limits for a single message, and a reply truncated mid-sentence loses precisely the disclosure it exists to deliver. The floor of 20 characters exists because a two-word reply cannot carry the brand name and a contact route.
How to fix itremediation
Trim each auto-reply to fit within 320 characters while keeping the brand name, the STOP instruction and the rates notice — those are the elements other rules require. If it will not fit, drop the marketing language rather than the disclosures.
A compliant exampleexample
Acme Coffee: for help email support@acmecoffee.com. Reply STOP to unsubscribe.
Notesnotes
Bird and Sinch cap at 255; Twilio and Bandwidth at 320. The 320 ceiling is used with the tighter 255 recorded as a provider divergence.
Rules you will hit next
Other campaign rules at the same severity. A registration is judged as a whole, not rule by rule.
CMP-016Contact email and phone must contain no spacesHighHIGHCMP-023Declared embedded links must come with a sample URLHighHIGHCMP-041The description must say how often the messages comeHighHIGHCMP-042A programme that asks for money must say soHighHIGHCMP-048Emergency framing requires the emergency use caseHighHIGHCMP-051A first-party lender must use the phrase the reviewer looks forHighHIGH
CMP-AUTOREPLY-LEN is one of 94 campaign rules in the 915-rule 10DLC registry. Free to cite under CC BY 4.0.