1. Login to QuickBooks Online: https://qbo.intuit.com/
** Notes: once you are logged in, you could go straight to https://app.qbo.intuit.com/app/accountsettings?p=company_billing
And skip first 4 steps
2. Click on the Gear Menu on the top right of the home screen
3. Click on “Account and settings” under YOUR COMPANY
4. Click “Billing & Subscription” on the left menu bar
5. Your Company ID number is a 12 to 18 digit number