# Cardkey Smartpass

Everything you need to understand Cardkey Smartpass

## Card format Overview

A proprietary 34-bit card format used in access control systems, featuring a unique structure composed of 14-bit site code and 16-bit card number, allowing for easy management and avoiding card number duplication for secure, contactless access.

## Cardkey Smartpass format properties

### Site Code

14 bits. The facility code range is 0 to 16,383.

### Card Number

16 bits. A unique serial number (0-65,535) for each card within that facility code.

### 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 | 6400064<br>Copy |
| Decimal | 104857700<br>Copy |
| Binary | 00000000110010000000000000001100100<br>Copy |

## The API that turns phones into key fobs.

[Get started](/content/signup/index.html)