You can have multiple company files in a single account with no limit, Roy.

Firstly, we can have multiple company files under the same Intuit account. However, each of your company files will require a subscription.

You can also open a new company file and start fresh without affecting your archived file, as each of your company files will be treated as a separate entity, which you can manage individually.

For further information and detailed guidance about creating another company file, please refer to this article: Create or add another company file to QuickBooks Online.

Additionally, you can check out this article to learn how to back up your company file in QuickBooks Online Advanced: Back up and restore your QuickBooks Online Advanced Company.

Let me know if you have further concerns about having multiple company files. Keep safe.