# ISCS 38bit

Everything you need to understand ISCS 38bit

## Card format Overview

A proprietary 38-bit card format used in access control systems, featuring a unique structure composed of 10-bit site code and 22-bit card number, and 2 parity bits (even and odd), allowing for easy management and avoiding card number duplication for secure, contactless access.

## ISCS 38bit format properties

### Site Code

10 bits. The facility code range is 0 to 1,023.

### Card Number

22 bits. A unique serial number (0-4,194,303) for each card within that facility code.

### Even parity

Even Parity for Even parity over bits 1-17.

### Odd parity

Odd Parity for Odd parity over bits 19-37.

### Generate examples

Put in the values for this card format, we'll generate the results in a few different formats.

### Here's your example

| Format   | Value                                                                 |
|----------|-----------------------------------------------------------------------|
| Hex      | 20320000C8<br>Copy                                                    |
| Decimal  | 138277814472<br>Copy                                                  |
| Binary   | 10000000110010000000000000000011001000<br>Copy                      |

## The API that turns phones into key fobs.