Answers
Frequently asked questions
Everything buyers ask about compatible RFID credentials — what they are, how to identify your format, ready-encoded credentials vs compatible blanks, and how ordering works across 369 formats.
Compatible vs genuine
What is a compatible access card?
A compatible access card is an independently manufactured credential encoded by specification to read identically to an original card on your existing readers. It is not an OEM-branded product — it presents the same frequency, data format and card number your access-control panel already accepts, usually at a fraction of the original manufacturer's price.
Are your cards genuine OEM cards?
No — our credentials are independently manufactured to be compatible with these systems, not OEM-branded products, and we're always clear about that. Each one is engineered to the same format your readers already accept. Security ID Systems is independent and is not affiliated with, authorized by, or endorsed by any access-control or lock manufacturer.
Will a compatible card work in my existing system?
Yes, when it is encoded correctly. We match the frequency, the bit format and — where it applies — your facility code and card-number range, so the reader cannot tell the difference. We confirm compatibility before anything is produced, so you are never guessing.
Identifying your card
What format is my access card or key fob?
Most cards print a part number or format name you can read directly; the reader brand by the door is another strong clue. Frequency is the first fork — 125 kHz low-frequency or 13.56 MHz high-frequency. Our identify-your-card guide walks through reading the markings, checking frequency and photographing your reader.
How do I tell 125 kHz from 13.56 MHz?
The printed part number usually reveals it, and the reader model confirms it. 125 kHz (LF) covers most legacy proximity cards like HID Prox, Indala and AWID; 13.56 MHz (HF) covers smart cards like MIFARE, DESFire and iCLASS. Send us a photo if you're unsure and we'll identify it for you.
Can you identify my format from a photo?
Often, yes. A clear photo of both sides of the card and the reader by the door is usually enough for us to determine the frequency, OEM and likely format. If it isn't conclusive, a sample card read on our equipment settles it.
Replacements & spares
Can you supply a replacement or spare for my existing card or fob?
For open formats — like EM, HID Prox and legacy iCLASS — yes, we encode a compatible replacement directly onto a programmable blank that reads identically. For secured smart credentials (AES, Seos), we supply compatible blanks your own system enrols. We always tell you which path applies to your format before you order.
Which cards are supplied as blanks for re-enrolment?
Secured smart credentials keep their keys under the system owner's control by design — MIFARE DESFire (AES), HID Seos, HID iCLASS SE and Elite, and similar. For these we supply compatible blank credentials on the matching chip platform, including genuine NXP DESFire, which your integrator enrols — exactly like ordering blanks through the original vendor's channel.
Is it legal to buy a compatible card?
Supplying a compatible credential for access you are authorized to use is a routine, legitimate part of the security-hardware market — the same way aftermarket keys and parts exist for many products. We supply credentials for your own access only, and decline anything we cannot legitimately produce.
Chips, formats and frequencies
What is a T5577 card?
The T5577 is a programmable 125 kHz chip that can be written to emulate dozens of proximity formats — HID, Indala, AWID, EM and many proprietary layouts. It is the universal blank most 125 kHz compatibles are encoded onto, which is why one chip can stand in for many different original cards.
T5577 vs EM4305 — what's the difference?
Both are rewritable 125 kHz chips. The T5577 is the most widely supported programmable blank and emulates the broadest range of formats; the EM4305 is a capable secondary blank used for EM-family and some other emulations. For most compatible proximity work the T5577 is the default, and we choose the right chip for your specific format.
What's the difference between 26-bit and 35-bit Corporate 1000 cards?
26-bit H10301 is the open, industry-standard Wiegand format — an 8-bit facility code and 16-bit card number anyone can produce. 35-bit Corporate 1000 is a registered HID high-security format with a larger card-number space and controlled facility codes. We supply compatible credentials for both, including the harder-to-source Corporate 1000 layouts.
What is the MIFARE family?
MIFARE is NXP's family of 13.56 MHz smart-card chips — Classic, Plus, Ultralight and DESFire — used across access control, transit and hotels. We build our 13.56 MHz cards on genuine NXP silicon. Each tier has different security: Classic and Ultralight are widely compatible, while DESFire uses AES encryption, so for those we supply compatible blanks your own system enrols rather than a direct copy.
Ordering, pricing and shipping
How much do compatible cards cost?
Pricing depends on the format, chip and quantity, but compatible credentials are consistently a fraction of the original manufacturer's list price — that price gap is the whole point. Every order is quoted, so you see the cost before you commit. Send your format and quantity for a quote.
How do I order?
Send the format printed on your card or a photo of your reader, plus how many you need, through our contact form or by email. We confirm compatibility, quote the credential, and produce it once you approve. There is no automated checkout yet — every order is verified first.
Do you ship worldwide?
Yes. We serve customers worldwide and ship compatible credentials internationally. Tell us your location when you request a quote and we'll include shipping in the response.
Can you supply cards in bulk for a facility?
Yes. Bulk and reorder quantities are a core part of what we do — for property managers, integrators, hotels and locksmiths. We match your facility code and card-number range so every credential drops straight into your system, and we keep your format on file for fast reorders.
Can you match my facility code and card numbers?
Yes, for the open and reproducible formats. Provide the facility code and the card-number range you need (or a working sample to read) and we encode each credential to match, so they integrate with your existing system exactly.
Specific systems
Can you supply a compatible Kastle or other managed-access card?
Managed-access credentials are deliberately locked to the provider, which is why spares are hard to get. These specialist, no-blanks-sold formats are exactly our specialty — when we can supply a compatible credential for a managed format you're authorized to use, we will, and we tell you plainly when a format needs a sample to read first.
Do you cover hotel lock key cards?
Yes — compatible blanks for the major hotel locking systems including VingCard, Saflok, Onity and Salto, plus specialty European and Japanese formats. Hotels typically buy these in bulk and reorder; we supply the matching blank for your lock platform for your system to encode.
Do you sell readers or just credentials?
We focus on compatible credentials — cards, key fobs and tags — not readers or panels. Our job is to supply the credential that works with the equipment you already have, which is where the specialist-format expertise matters most.
Request a quote
Can't find your format? Email the specialists.
Send the part number printed on your card or a photo of the reader. We confirm compatibility before you order — and we cover the specialist formats nobody else lists.