> For the complete documentation index, see [llms.txt](https://key.hideez.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://key.hideez.com/faq/how-many-rfid-keys-can-be-written-to-one-hideez-key-device.md).

# How many RFID keys can be written to one Hideez Key device?

FAQ — Question 7

At the moment, you can write to Hideez Key only one RFID key. Initially, the key stores a unique RFID.

It can be entered into the Access Control System and used without modifications.

If necessary, its (RFID) can be rewritten to any that you selected using the programmer.

The RFID protocol used (125 kHz HID and Em-Marine standard).