{
  "id": "OPS-065",
  "slug": "ops-065",
  "title": "A carrier opt-out is authoritative even if your list has no record",
  "statement": "A delivery rejection indicating the carrier holds an opt-out for the number must be treated as a suppression event in its own right.",
  "rationale": "Carriers maintain their own opt-out state, and a consumer who texted STOP to a shared originator or used a handset-level block can be opted out there while your list shows them active. Retrying that number burns delivery reputation and, more importantly, means you are trying to message somebody who has revoked — your own list not knowing about it is not a defence.",
  "layer": "OPERATIONAL",
  "layerSlug": "operational",
  "object": "delivery error stream into the suppression list",
  "severity": "HIGH",
  "detectability": [
    "UNDETECTABLE_PRE_SUBMISSION"
  ],
  "failureClass": "TERMINAL_EXTERNAL",
  "authorities": [
    "Bandwidth",
    "all MNOs"
  ],
  "applicabilityText": "Applies to every 10DLC registration.",
  "universal": true,
  "remediation": "Write back to the suppression list on every opt-out-class delivery error rather than counting it as a failed send. Done when a carrier-held opt-out appears in your own suppression list within a day of the first rejection.",
  "example": "Delivery error 21610 (opted out) → suppress the number locally, channel=carrier, and stop retrying.",
  "notes": "Reaches you as a delivery code after launch. What the user has to establish is whether their platform surfaces opt-out-class errors distinctly, and whether anything consumes them — the common answer is that they land in a failure metric nobody reads.",
  "phase": "post",
  "automated": false,
  "attestation": {
    "question": "Does anything in your systems consume opt-out-class delivery errors and write them to the suppression list?",
    "howToCheck": [
      "Ask whether the platform surfaces opt-out-class errors distinctly from other delivery failures.",
      "Trace where they go. The common answer is a failure metric nobody reads.",
      "Done when a carrier-held opt-out appears in your own list within a day of the first rejection."
    ],
    "failureLooksLike": "A consumer opted out at the carrier or blocked the number on the handset, your list shows them active, and you retry — messaging somebody who has revoked. Your list not knowing is not a defence."
  },
  "url": "https://ekas.io/rules/10dlc/operational/ops-065/",
  "markdown": "https://ekas.io/rules/10dlc/operational/ops-065.md",
  "registry": "https://ekas.io/rules/10dlc/",
  "updated": "2026-07-25",
  "licence": "CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/"
}