> For the complete documentation index, see [llms.txt](https://help.security.gallagher.com/knowledge-hub/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.security.gallagher.com/knowledge-hub/products/cc-hardware/credentials/encoding-solutions/encoding-troubleshooting/encoding-troubleshooting-putting-site.md).

# Site Specific Keys do not transfer to Cardax IV-connected T-Series readers

Use an Admin Card to update Site Specific Keys on Cardax IV-connected T-Series readers.

If a site has T-Series readers connected to controllers via a Cardax IV connection instead of HBUS, the Cardax IV protocol does not support transferring Site Specific Keys to the reader. Gallagher's alternative method is the **Admin Card**.

This issue is specific to Cardax IV-connected T-Series readers only. HBUS-connected readers receive keys directly from the controller.

### Requirements

* The Admin Card feature is found on the **Server Properties** tab in Configuration Client.
* The card used as an admin card must be a **blank MIFARE Plus 4k or DESFire 4k card**, minimum.
* The site does not need encoding enabled on the licence, just a USB encoder.
* **"Allow Admin card update at readers"** must be checked for the card to work at Cardax IV-connected readers.

![Generate Admin Card dialog for Cardax IV T-series reader key update](https://328339335-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F6bM8WhlBE9BYizPWJaPN%2Fuploads%2Fgit-blob-63420a9e9bbadc420bf446012be1e217a4e7a0bd%2FSECHUB-ENCODING-TS-01-generate-admin-card-cardax-iv.png?alt=media)

### Update keys with an Admin Card

1. Go to Server Properties tab in Configuration Client.
2. Encode an Admin Card using a blank MIFARE Plus 4k or DESFire 4k card.
3. Present the Admin Card to the reader. The reader will flash white 3 times, then resume functionality with the new keys.

{% hint style="warning" %}
The Keys will be wiped if the reader is connected as a Cardax IV reader and you select **Reset to Factory Defaults** on the Status and Overrides page.
{% endhint %}

### Command Centre 8.30 and above

MIFARE keys, Classic, Plus and DESFire, are held on the controller, not in the reader. If the reader is connected as a Cardax IV reader, the reader can have its keys updated by presenting an Admin Card.

***

🔗 **Related**

* [Encoding Troubleshooting - Reverting to Default Gallagher Keys](/knowledge-hub/products/cc-hardware/credentials/encoding-solutions/encoding-troubleshooting/encoding-troubleshooting-reverting-to.md). What to export before you change a site back to the Gallagher Default keys.
* [Credentials - Fault Finding Cards with Site Specific Keys](/knowledge-hub/products/cc-hardware/credentials/credential-information/credentials-fault-finding-cards-with-s.md). Admin Card requirements and the version-specific key storage behaviour in full.
* [Credentials - Site Specific Key (SSK) vs Default Site Key](/knowledge-hub/products/cc-hardware/credentials/credential-information/credentials-site-specific-key-ssk-vs-d.md). How to tell which key a site is using.


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