A format is the structure of the data stored in an access control credential. It is comprised of a set of binary digits – “bits”– put together a certain way to create a binary number, which is converted into a credential number by an access control system. The number of ones and zeros, and how they are put together, determines the format and ultimately the credential number.
For example: A 26-bit format (H10301) is created like this
1-11111111-0001011111101100-1 with the first set of ones (in red) representing the site code and the second set of ones and zeros (in blue) representing the credential number. The access control system sees this format as card number 6124 with a site code 255. The 26-bit format is the most common format requested and can be used by most access control systems available today. However, there are many formats available and some formats are unique to access control systems and do not work with other formats at the same time. This is why it is so important to know the format when ordering credentials.
HID 26-Bit Format: H10301
The 26-bit format (Format number H10301) is the industry standard format, and consists of 255 possible facility codes. Within each facility code, there are 65,535 unique card numbers.
HID Proprietary 37-Bit Format: H10302
The 37-bit format can be used to program a wide range of unique credential numbers. Although it is available to all customers, not all access control systems can handle such a large data length format. In addition, many systems are unable to handle a format that does not have a facility code.
HID Proprietary 37-Bit Format with Facility Code: H10304
This 37-bit format has 65,535 facility codes available and over 500,000 card numbers within each facility code. Just like the 37-bit format without facility code, many systems are not capable of handling a format as large as 37 bits. In addition, many systems are not capable of handling a facility code as large as 65,535.
Corporate 1000 Format
The Corporate 1000 format is a 35-bit format with a unique Company ID Code and more than 1,000,000 available credential numbers. The Corporate 1000 format offers the end-user a large quantity of available credential numbers and is typically reserved for customers with the need or potential to badge a large number of cardholders. The Corporate 1000 format is also available to large, geographically diverse organizations with a requirement to unify the structure of their access control system around an exclusive access control card format under their control.