{
  "url": "https://proudtek.com/compatibility/onity-hotel-key-cards/",
  "sourceUrl": "https://proudtek.com/compatibility/onity-hotel-key-cards/",
  "title": "Onity Hotel Key Cards — Compatibility Guide",
  "description": "Procurement-grade compatibility reference for Onity (now Honeywell Building Automation, formerly Carrier Global Access Solutions and originally TESA /...",
  "kind": "article",
  "imageUrl": "https://proudtek.com/landing-images/hero/compatibility-onity-hotel-key-cards.webp",
  "imageAlt": "Onity Trillium hotel lock with MIFARE Plus and BLE DirectKey hotel key card compatibility",
  "imageGallery": [
    {
      "url": "https://proudtek.com/landing-images/hero/compatibility-onity-hotel-key-cards.webp",
      "alt": "Onity Trillium hotel lock with MIFARE Plus and BLE DirectKey hotel key card compatibility"
    }
  ],
  "breadcrumbs": [
    {
      "name": "Home",
      "url": "https://proudtek.com/"
    },
    {
      "name": "Compatibility",
      "url": "https://proudtek.com/compatibility/"
    },
    {
      "name": "Onity Hotel Key Cards — Compatibility Guide",
      "url": "https://proudtek.com/compatibility/onity-hotel-key-cards/"
    }
  ],
  "summary": [
    "Procurement-grade compatibility reference for Onity (now Honeywell Building Automation, formerly Carrier Global Access Solutions and originally TESA /..."
  ],
  "faq": [
    {
      "question": "How do I identify the Onity lock generation before ordering cards?",
      "answer": "Three indicators usually settle it: the lock-face badge (HT22 / HT24 / HT28 are explicitly named; ADVANCE / integra / Trillium each have distinct escutcheon geometry), the encoder model at the front desk (PP32 portable = HT-era or Trillium; Encoder 4000 = current; Encoder 2100 = integra-era), and the firmware version reported by an Onity service tool against any sample door. If all three are unclear, send a current guest card sample to the supplier for an inspection read before committing to a production chip. Note that 'Onity Innspire' searches often reflect a third-party AI hospitality platform that integrates with Onity locks — Innspire is not an Onity product."
    },
    {
      "question": "Who owns Onity in 2026, and is the parent likely to change again?",
      "answer": "Honeywell Building Automation acquired Onity through Carrier's Global Access Solutions business on 3 June 2024 for approximately $4.95 billion. In February 2025 Honeywell announced a planned corporate split into separate Automation and Aerospace companies in H2 2026; Onity will move into the new Automation entity. Procurement teams writing about Onity in 2026 should use the framing 'Onity, a Honeywell brand (planned for the Automation spin-off in H2 2026)' to keep references accurate."
    },
    {
      "question": "Can one card SKU cover both ADVANCE and Trillium doors in the same estate?",
      "answer": "Yes if the SKU is MIFARE Classic 1K — Classic reads on the HT24 / HT28 RFID hybrid, ADVANCE, integra and Trillium reader heads. A MIFARE Plus SKU also works as long as the encoder writes Plus in SL1 mode for the ADVANCE reader heads (SL3 for integra and Trillium). DESFire-only SKUs should be avoided on Onity estates unless Onity service has explicitly confirmed DESFire support for the specific reader heads in scope — DESFire is not advertised as a standard credential across Onity's English-language product pages."
    },
    {
      "question": "Is the 2012 Onity HT-series vulnerability still relevant for new card orders in 2026?",
      "answer": "The Cody Brocious DEF CON 20 disclosure (July 2012) affected HT-series locks via the DC charging port on the underside of the lock; a ~$50 device read a 32-bit sitecode from lock memory through the one-wire interface and replayed it. No formal public CVE identifier was ever assigned, which is itself an unusual gap in the NIST National Vulnerability Database for a disclosure of this scale. Onity's remediation combined a free plastic port-shield kit (with Torx screws) and a paid firmware upgrade; many properties accepted only the free mechanical fix. A new card order does not by itself mitigate or expose the issue. Properties with HT-series locks still in service should confirm with Onity service that the controller is on the remediated firmware line (or has the port-shield kit installed) before ordering new card stock. The Trillium upgrade path eliminates the exposure entirely by replacing the HT control board."
    },
    {
      "question": "What encoder do I need for MIFARE Plus SL3 on an integra estate?",
      "answer": "Encoder 2100 with current firmware supports Plus SL3 AES-128 encoding; Encoder 4000 is the preferred unit for new rollouts. Encoder 1100 cannot issue Plus in SL3 and should be upgraded before any Plus SL3 stock is ordered. Encoder firmware (not OnPortal version) is the limiting factor — verify with Onity service before placing the order."
    },
    {
      "question": "Does DirectKey require the property to run a specific mobile app?",
      "answer": "Onity provides a default DirectKey-branded app, but larger hospitality groups typically integrate DirectKey into their own branded app via the Onity mobile SDK. Both options present the same BLE credential to the lock — the integration is a guest-experience choice rather than a technical constraint. The Hilton Honors Digital Key programme (rolled out across 100+ Hilton properties starting February 2016) is the largest documented DirectKey deployment in branded-app form."
    },
    {
      "question": "Does Onity support Apple Wallet and Google Wallet keys?",
      "answer": "Yes on Trillium reader heads with current firmware — wallet keys are emulated as NFC credentials. Verify with Onity service which firmware line enables wallet emulation on the specific property; wallet support on integra is less consistent. Properties wanting wallet keys at scale should confirm the back-end DirectKey app server is configured for wallet-credential issuance."
    },
    {
      "question": "Will premium-material cards (1.0 mm bamboo or wood) read reliably on Onity?",
      "answer": "On integra and Trillium reader heads they read reliably — these readers are tuned for card stacks up to roughly 1.2 mm. On ADVANCE reader heads premium thickness can be marginal above 0.9 mm because the antenna resonance was tuned narrower. If the estate has any ADVANCE doors in scope, pilot a production-thickness sample on the actual hardware before committing to a full order."
    }
  ],
  "procurementFields": [],
  "collectionGuidanceFields": [],
  "coreGuidanceFields": [],
  "articleGuidanceFields": [
    {
      "label": "Best for",
      "value": "Onity Hotel Key Cards — Compatibility Guide supports RFID and NFC evaluation, comparison, and sourcing decisions."
    },
    {
      "label": "Compare first",
      "value": "Compare Onity Hotel Key Cards — Compatibility Guide against reader compatibility, chip family, material, and deployment environment."
    },
    {
      "label": "What to confirm",
      "value": "Confirm target application, compatibility requirements, customization needs, quantity, and sample expectations before quoting Onity Hotel Key Cards — Compatibility Guide."
    }
  ],
  "sourceLinks": [],
  "related": [],
  "productSpecs": [],
  "machineJsonUrl": "https://proudtek.com/machine/compatibility/onity-hotel-key-cards.json",
  "machineTextUrl": "https://proudtek.com/machine/compatibility/onity-hotel-key-cards.txt",
  "author": {
    "name": "Mia Li",
    "title": "Quality & Manufacturing Engineer",
    "expertise": [
      "RFID card materials",
      "Hotel key card manufacturing",
      "Compliance (ISO, CE, RoHS)",
      "Laundry tag durability"
    ]
  },
  "publisher": "Proud Tek Co., Limited",
  "datePublished": "2026-04-22",
  "dateModified": "2026-06-10T18:00:00Z",
  "reviewedBy": "Proud Tek Editorial Team",
  "lastReviewedDate": "2026-06-10T18:00:00Z",
  "credentials": [
    "ISO 9001:2015",
    "ISO 14001:2015",
    "RoHS Compliant",
    "CE Marking",
    "REACH Compliant"
  ],
  "generatedAt": "2026-03-16T01:42:30.697Z"
}