Hi there, Advanced_User.

Thank you for visiting again the QuickBooks Community. I'll be sharing different details on how separating accounts in QuickBooks Online works. Then, to ensure you're able to achieve this matter.

If you're referring to have a separate QuickBooks Online account, it only allows one company per subscription. That said, you'll have to purchase a second subscription for a new account. Then, once you already have an existing account, you can use the same login credentials when signing up. This lets you quickly switch between companies so you can manage everything more efficiently.

To see further details and how to perform the process, you can click each article below. These provide about managing multiple company files.

• Create or add another company file to QuickBooks Online.
• How do I switch companies?.

If you mean to create separate liabilities account in the Chart of Accounts, I suggest adding a new one. This enables you to create new details for your other liability and make sure to enter different information like adding extra characters for the account name. This is to make sure that you're able to save the details. Before doing the steps below, I recommend consulting with an accounting professional so you can receive the best legal advice for your business. 

Here's how:

1. Click the Gear icon and select Chart of Accounts.
2. Click the New button in the top right corner. 
3. Click on the Account Type drop-down to select the account type.
4. Select the Detail Type to specify the type of account that you want to add.
5. Enter the name of the account in the Name field.
6. You have the option of including information in the Description field and an amount in the Balance field. 
7. Click Save and Close.

You can open this article to see additional information: Learn how to set up and add accounts to your chart of accounts.

Additionally, please refer to this article to view detailed steps on how to create subaccounts to break down your expenses, income, and more: Create subaccounts in your chart of accounts in QuickBooks Online.

Don't hesitate to comment below if you need further help managing your accounts in QuickBooks?. I'm always here to assist you.