> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://help.tmdlocks.com/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# Find the serial number of your lock

The serial number is the unique number of your TMD Chain Lock. You need it when you register your lock with your insurer or leasing provider. Because the lock has no physical keys, you enter the serial number in the field that asks for a key number.

###### Find the serial number in the app

1. Open the app.
2. Go to **"Lock information"**.
3. Here you can see the serial number of your lock.

###### Find the serial number on the packaging

The serial number is also printed on the packaging of your lock.