BQT, ISCS & Australian Wiegand Formats Explained

The Australian Access-Control Landscape

Australia's enterprise access-control market developed largely independently of the North American mainstream. Integrators adopted local panel and reader vendors — most notably BQT Solutions — whose proprietary Wiegand formats never became international catalog items. The result is that facility managers maintaining BQT or ISCS installations often find that mainstream card suppliers either cannot supply compatible credentials at all or supply only standard 26-bit cards that the readers will reject.

The root cause is straightforward: Wiegand readers are programmed to accept a specific bit-width and a specific site code. A 26-bit card presented to a reader configured for BQT 34-bit will simply not decode. Understanding the exact bit structure of each ANZ format is therefore the first step toward sourcing a card that will actually work — and the same principle applies whether you are replacing a handful of lost cards or re-issuing credentials across an entire campus.

Both BQT and ISCS formats transmit data on standard 125 kHz LF proximity technology, the same radio layer used by HID EM4100, Indala, and most other 125 kHz proximity cards and fobs. The proprietary element is entirely in the data layer — the bit count, parity placement, and field layout — not in the carrier frequency or physical form factor.

BQT 34-Bit and 38-Bit (with Issue Level) Decoded

The BQT 34-bit format follows a layout of: one leading even-parity bit, an 8-bit facility (site) code field, a 24-bit card number field, and one trailing odd-parity bit — totalling 34 bits. The 8-bit site code supports values from 0 to 255, and the 24-bit card number field supports values up to approximately 16.7 million, giving installations substantial headroom before card numbers repeat within a facility code.

BQT's 38-bit variant extends the base structure by inserting an Issue Level field. The Issue Level is a small numeric field — typically 4 to 8 bits depending on the specific firmware version — that allows a facility to re-issue a credential with an incremented issue number without changing the card number itself. This is operationally useful in high-turnover environments: a lost card can be invalidated at the panel by issue level, and the replacement card carries the same number but a higher issue value. When ordering BQT 38-bit compatible cards, the issue level value must be specified along with the site code and card number range.

Because both BQT formats use T5577 or EM4305 writable 125 kHz substrates as their physical base, compatible credentials can be encoded to either format once the facility code, card number sequence, and — for the 38-bit — issue level are confirmed. Our T5577 explained guide covers how this programmable blank underlies most LF proximity compatible credentials.

ISCS 38-Bit Decoded

The ISCS 38-bit format is structurally distinct from both BQT variants. It opens with a single leading even-parity bit, followed by a 10-bit site code field, a card number field occupying the remaining bits to reach the 38-bit total, and appropriate trailing parity. The 10-bit site code is the key differentiator from BQT 34-bit: it supports site code values from 0 to 1023, roughly four times the range of the 8-bit BQT field, and was likely specified to accommodate ISCS installations across large campuses or multi-building estates where individual buildings each require a distinct site code.

ISCS installations are less common than BQT deployments in the Australian market but are found in healthcare, education, and government sites where the broader site-code space was a procurement requirement. Compatible ISCS 38-bit proximity cards must be encoded with the precise 10-bit site code value from the existing installation — a site code that reads as, for example, 512 in a BQT context would carry an entirely different binary value in ISCS 38-bit and would not be interchangeable.

Facilities that are unsure whether their installation is ISCS 38-bit or a BQT variant should consult their panel programming documentation or the installer's commissioning sheet. The card format identification guide explains how to read panel logs or use a Wiegand monitor tap to confirm the bit count and site code your readers are currently accepting.

Encoding Compatible Cards to These Formats

All three ANZ formats — BQT 34-bit, BQT 38-bit with Issue Level, and ISCS 38-bit — reproduce on T5577 or EM4305 programmable 125 kHz blanks once the bit layout parameters are matched. The encoding process writes the facility code, card number, issue level (where applicable), and computed parity bits to the chip's data pages in the correct sequence. The resulting credential is electrically and logically indistinguishable from a factory-issued card to the reader and panel.

Because these formats are not widely supported in generic card-programming software, encoding is typically done at the supplier level rather than on-site. When placing an order for BQT 34-bit compatible cards, customers supply the site code and the starting card number (or a specific number range); the cards arrive pre-encoded and ready to present to the access panel for enrollment. No on-site programmer is required.

For multi-format or mixed-vendor sites — which are not uncommon in Australian commercial buildings that have been extended or refurbished over several decades — it is worth confirming the exact format of each reader zone before ordering. A building might run BQT readers on the car park and ISCS readers on a heritage wing, each requiring a separate card type. Our complete Wiegand format guide explains how to distinguish formats and why a card correct for one zone will not work in the other.

Ordering Compatible ANZ Credentials

When ordering compatible credentials for BQT or ISCS installations, the minimum information required is: the format (BQT 34-bit, BQT 38-bit with Issue Level, or ISCS 38-bit), the facility or site code currently programmed in the panel, and the card number or range needed. For BQT 38-bit orders, the current issue level value is also required. If any of these values are unavailable, the format identification guide describes how to recover them from panel software or by reading an existing card with a compatible reader.

ANZ format cards are available as ISO CR-80 clamshell proximity cards, thin PVC cards suitable for inkjet or dye-sublimation printing, and key fob form factors. All form factors use the same 125 kHz LF data layer. Bulk orders are encoded to the customer's site code and sequential card number range; custom-range or non-sequential numbering is also supported on request. The office building and commercial tenant access cards solution page covers multi-format ordering for facilities with mixed credential populations.

For context on how ANZ proprietary formats compare to other regionally common non-standard formats — such as the Lenel 42-bit card or the Software House CCOTZ 37-bit card — the Wiegand format guide provides a full cross-reference. Security ID Systems is an independent manufacturer and supplier of compatible access-control credentials and is not affiliated with, authorized by, or endorsed by BQT Solutions or ISCS.