No Products in the Cart
You have a card or fob in your hand, the reader beeps when you present it, and now you need more of them. The problem is that nothing on the credential obviously says what it is. The box is long gone, the installer moved on, and ordering the wrong format means the new cards simply will not open the door. Figuring out the format of your access card is one of the most common — and most frustrating — questions in access control.
The good news: Most credentials carry enough clues to identify the format and part number, if you know where to look. This guide walks through the printed markings, the frequency, the facility code, and the reader and panel details that together tell you exactly what to reorder. And if the clues run out, we will identify a sample for you.
Free samples are available so you can test compatibility before you buy: Request a free sample credential to test against your reader
Before you flip the card over, it helps to know what you are looking for. A working replacement credential has to match three separate pieces of information:
Format plus facility code plus card number is the combination that makes a credential work. Most identification work is about recovering the first two, because the card numbers are just the next available range you assign.
Almost every access credential falls into one of two radio frequencies, and knowing which one narrows the field immediately.
A quick field test: Hold a standard NFC reader app on your smartphone near the card. If the phone detects a tag, you are almost certainly holding a 13.56 MHz smart card. If nothing happens, the credential is very likely a 125 kHz prox card, because typical phones cannot read that low-frequency band. This is not definitive — some 13.56 MHz cards use secured sectors a phone will not fully read — but it reliably tells you which side of the frequency line you are on, which is often half the battle.
With the frequency narrowed, turn the credential over and read it closely, ideally under good light or with a magnifier. Manufacturers print small but useful information on most cards.
Look along the top or bottom edge on the back of the card. You will often find:
Two important cautions: First, the facility code is not always printed — on many HID prox cards it is encoded internally and never appears on the surface, so a card with only one visible number is common. Second, the externally printed number may not match the internally encoded number, especially on extended formats. Treat printed numbers as strong hints, then confirm against your panel or packaging.
Fobs compress the same data onto the flat face opposite the ring loop, or along the thin edge. Some fobs print a full part number and ID; others omit the format entirely and show only a card number. If a fob is unmarked, the reader and panel details (Step 4) become your best path.
Once you have a part number, a brand name, or a bit count, you can line it up against the common formats. Here is where the printed clues turn into a specific, orderable credential. Match what you see to the closest entry below and follow the link to the exact compatible credentials:
If your card names a format that is not listed above, browse all proprietary formats or send us an email at support@authoriz-id.com; our U.S.-based tech support will respond the same day and will get you what you need!
Plenty of credentials arrive with no useful markings at all. When that happens, the surrounding hardware and paperwork carry the answer:
Once the format is settled, decide which physical credential fits how your people will use it. The same format is usually available in several form factors:
If the markings are worn, the box is gone, and the software is locked down, you do not have to guess. This is the fastest, surest path when self-identification runs out:
Our U.S.-based support team does this every day, and there is no charge to have a sample identified. It removes the risk of ordering a full batch of the wrong format.
Contact Our U.S.-Based Tech Support Team - phone: (970) 682-0765 - email: support@authoriz-id.com
To pull it all together, work the steps in order: check the frequency to split 125 kHz from 13.56 MHz, read the printed part number and markings for a format and facility/card string, match those clues to a known format, and fall back to the box, software, and hardware whenever the card is blank. When any doubt remains, have a sample identified and then test one credential on your own reader before committing to a full order. That final live test is what turns a confident guess into a certainty.
The surest way to confirm you have identified the right format is to hold a single sample credential to your own reader and watch the door respond. Once we help you pin down the format and facility code, a free test card lets you prove compatibility on your exact system before you buy in quantity.
Get in touch to claim a free sample credential and confirm your format
