Discontinued & Obsolete Access Card Formats: How to Replace Them

Why OEMs Discontinue Card Lines

Access control manufacturers retire credential lines for reasons that have nothing to do with the underlying technology. Corporate acquisitions are the most common trigger: when Interlogix absorbed GE Security, when Honeywell consolidated several brands, or when dormakaba merged Kaba with Dorma, entire product lines were quietly sunset in favour of the acquirer's current platform. The installed base — often tens of thousands of readers — is left to age in place.

Platform migration is the second driver. Manufacturers have a strong commercial incentive to push customers toward newer, higher-margin smart-card ecosystems. Discontinuing a legacy 125 kHz credential removes an easy reason to stay on the old platform. From the OEM's perspective, a stranded site is a sales lead for a full system upgrade. From the facility manager's perspective, it's a budget crisis that may be years away from approval.

The practical result is that legacy OEM proximity formats remain in service long after the credential is no longer available through normal distribution channels. Understanding this gap is the first step toward solving it cost-effectively.

Common Stranded Formats: Casi-Rusco, Flexpass, Cardkey and More

Casi-Rusco produced several distinct proprietary encoding schemes — an F2F 12-digit magnetic stripe variant, a GE/Interlogix C10106 26-bit proximity format, and a 40-bit HID FSK variant among them. After the Interlogix acquisition and subsequent wind-down, each of these became orphaned. A site holding several hundred Casi-Rusco C10106 compatible proximity cards on existing Casi readers has no OEM replacement path — but the format specification itself is well-characterised and remains reproducible.

Motorola's Flexpass platform is another widely cited stranded format. Originally deployed across commercial and government sites in North America, Motorola Flexpass compatible cards are no longer manufactured by the OEM but the reader hardware — which enforces a specific 26-bit or custom Wiegand structure — is still operational at a significant number of facilities. Similarly, the Cardkey SmartPass compatible card serves sites where Johnson Controls inherited and then discontinued the Cardkey product range.

Continental Access and Keyscan installations represent a further stranded cohort. Continental's NAPCO-era proximity formats used proprietary bit structures that differ from generic 26-bit H10301, making off-the-shelf cards incompatible without format-specific encoding. Keyscan systems — common in multi-tenant commercial buildings across Canada — use a proprietary 56-bit format that is not interchangeable with standard Wiegand credentials. Keyscan C15001 compatible proximity cards keep those installed systems alive without reader replacement.

Why You Do Not Have to Replace the Readers

The reader is the expensive component. A single Wiegand proximity reader costs between $80 and $300 at the panel end; a full site with 40 doors, controllers, cabling, and commissioning can represent a six-figure capital project. The credential is a consumable — its replacement cost is orders of magnitude lower. Provided the original format was a non-keyed 125 kHz LF credential, the reader has no mechanism to distinguish a compatible from an original: it processes the incoming bit stream, validates the facility code and card number, and passes the decision to the controller. Format fidelity is everything; the physical origin of the card is irrelevant to the reader.

This is a structural feature of how 125 kHz proximity works. There is no cryptographic handshake, no key negotiation, no certificate chain. The reader interrogates the transponder, receives a modulated bit stream in a defined encoding (FSK, PSK, or ASK depending on the format), decodes it, and transmits the result over Wiegand or Clock-and-Data to the controller. A credential that presents the correct bit structure — facility code, card number, parity — passes every time. This is why 125 kHz LF proximity cards and fobs remain a reliable replacement target for legacy installs.

Sites that have already identified their format can proceed directly to ordering. Sites uncertain of their format — particularly where the original card is unlabelled or the system documentation has been lost — should first work through the process for identifying an access card or key fob format before placing a replacement order.

How a Compatible Credential Is Mapped from a Sample

Producing a compatible credential for a discontinued format requires characterising the original's modulation, data rate, bit structure, and encoding scheme. For well-documented formats — HID 26-bit H10301, EM4100, and most standard Wiegand variants — this information is publicly specified and the production path is straightforward. For proprietary OEM formats, the process begins with a reference sample from the customer's existing credential stock.

The sample card is read in a calibrated RF environment to extract the raw bit stream. The modulation type (most Casi-Rusco and Cardkey variants use FSK; Indala uses a distinctive PSK with a different carrier frequency) is identified and the data structure is decoded against known proprietary Wiegand extensions. Once the encoding map is confirmed against at least two or three sample cards — to verify facility code placement, card number field width, and parity algorithm — the format can be reproduced on compatible transponder media. For readers that accept Continental C10202 compatible proximity cards, for instance, this mapping exercise confirms the exact 35-bit or custom Wiegand structure before any production run begins.

This process is why it matters to provide sample credentials when ordering replacements for obscure or undocumented formats. It is also worth reading an honest comparison of compatible versus genuine access cards to understand what is and is not being reproduced — the credential number and format are; no secured cryptographic material from a smart card system ever is.

Ordering Replacements for an Obsolete System

The ordering process for a discontinued format mirrors any bulk credential order, with one additional step: format verification. A facility manager should gather three to five sample cards from the existing stock, note the system brand, reader model number if known, and any markings on the card face (facility code stickers, numbering sequences, or partial OEM part numbers are all useful). This information, submitted with a sample, allows the format to be confirmed before production.

Card numbers for replacement batches are typically assigned to follow on from the site's existing number sequence — preserving the existing database without re-programming the access control panel. For sites that need cards numbered to match a specific existing range, sequential encoding from a defined start number is standard. Buying compatible access cards in bulk covers the practical logistics of minimum order quantities, number sequencing, and lead times in more detail.

Magnetic stripe variants — such as the Casi-Rusco compatible magstripe card or Casi-Rusco F2F 12-digit compatible magstripe card — follow the same process, with the additional specification of track assignment and character encoding. F2F encoding is specific to Casi-Rusco magstripe readers and requires a different write process than standard ISO 7811 tracks; this is another case where a format sample is essential before production.

Security ID Systems is an independent manufacturer and supplier of compatible access-control credentials and is not affiliated with, authorized by, or endorsed by Casi-Rusco, Motorola, Cardkey, GE Security, Interlogix, Continental Access, Keyscan, or any other brand referenced on this page.