Every Youtube account has a unique user ID (indentification number). It is a long string with mix of alphabets and numbers. User ID details in Youtube account is not directly listed on the main setting page. Instead you need to to navigate further within settings to find the unique user ID number of the Youtube account.
Check User ID details of your Youtube channel
1. Open Youtube.com website and login into your account. After login, click on Settings option to open Settings page. (Click on your account name at top right and then click Settings in the expanded menu).
2. On the Settings page, click on Overview tab option on left. Then under “Account Information” click on “Advanced” option in the “Name” section. Alternatively, you can directly use (youtube.com/account_advanced) URL to open advanced settings page.
3. On the Advanced Settings page, your Youtube User ID is listed at the top part under “Account” section. It is a long string of characters including alphabets and numbers.
You can copy or note it down for future reference for specific purpose while dealing with activites related to your Youtube channel (or account).