{
  "id": "CMP-AUTOREPLY-LEN",
  "slug": "cmp-autoreply-len",
  "title": "Auto-reply messages must be 20–320 characters",
  "statement": "The opt-in, opt-out and HELP reply messages must each be 20–320 characters.",
  "rationale": "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.",
  "layer": "CAMPAIGN",
  "layerSlug": "campaign",
  "object": "campaign.help_message + optin_message + optout_message",
  "severity": "HIGH",
  "detectability": [
    "DETERMINISTIC"
  ],
  "failureClass": "RETRY_FIELD",
  "authorities": [
    "Twilio",
    "Bandwidth"
  ],
  "applicabilityText": "Applies to every 10DLC registration.",
  "universal": true,
  "remediation": "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.",
  "example": "Acme Coffee: for help email support@acmecoffee.com. Reply STOP to unsubscribe.",
  "notes": "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.",
  "catalogIds": [
    "CMP-007",
    "CMP-008",
    "CMP-009"
  ],
  "phase": "approval",
  "automated": true,
  "url": "https://ekas.io/rules/10dlc/campaign/cmp-autoreply-len/",
  "markdown": "https://ekas.io/rules/10dlc/campaign/cmp-autoreply-len.md",
  "registry": "https://ekas.io/rules/10dlc/",
  "updated": "2026-07-25",
  "licence": "CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/"
}