{
  "id": "OPS-142",
  "slug": "ops-142",
  "title": "A legitimately shared number needs a register of who sends on it",
  "statement": "Where a number or short code is shared under an approved arrangement, documented records of every message sender operating on it must be immediately available.",
  "rationale": "Sharing is permitted only where it can be unpicked, and the register is what unpicks it: a complaint about one message has to resolve to one sender within the time a carrier gives you, which is short. Without it a shared arrangement is indistinguishable from the sub-aggregation the previous rule prohibits, and it will be treated as such.",
  "layer": "OPERATIONAL",
  "layerSlug": "operational",
  "object": "shared-number sender register",
  "severity": "HIGH",
  "detectability": [
    "UNDETECTABLE_PRE_SUBMISSION"
  ],
  "failureClass": "TERMINAL_EVIDENCE",
  "authorities": [
    "T-Mobile",
    "CTIA"
  ],
  "applicabilityText": "Applies to every 10DLC registration.",
  "universal": true,
  "remediation": "Keep a current list of every sender on the shared number, with the approval that permits the arrangement, somewhere you can produce it the same day. Done when a message can be attributed to a sender without asking anybody.",
  "notes": "A register inside the operator, and no registration field even says the number is shared. What the user has to confirm is that the sharing arrangement was approved in the first place — an undocumented one is OPS-141, not this rule.",
  "phase": "post",
  "automated": false,
  "attestation": {
    "question": "If a number you send from is shared, was the arrangement approved — and could you attribute one message to one sender the same day?",
    "howToCheck": [
      "Confirm the sharing arrangement was approved in the first place. An undocumented one is a different and worse finding.",
      "Keep a current list of every sender on the number, with the approval that permits it, where you can produce it same-day.",
      "Test it: pick a message and attribute it without asking anybody."
    ],
    "failureLooksLike": "A complaint has to resolve to one sender inside the short window a carrier gives you. Without the register, a permitted shared arrangement is indistinguishable from prohibited sub-aggregation and gets treated as such."
  },
  "url": "https://ekas.io/rules/10dlc/operational/ops-142/",
  "markdown": "https://ekas.io/rules/10dlc/operational/ops-142.md",
  "registry": "https://ekas.io/rules/10dlc/",
  "updated": "2026-07-25",
  "licence": "CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/"
}