You should sign up for a new QBO account.

Regarding your first QBO account, you can convert it to QB Desktop file and use the trial version to access historical data for good.

Welcome to the Community space, @stevecar.

Let me help you set up your new company file in the same QuickBooks Online (QBO) account sign-in.

Adding a new company file to the same QBO account has its own paid subscription. Visit the QuickBooks pricing page and select the subscription option you want. This opens one of two experiences:

• If you're signed in to QuickBooks, you’ll be asked to confirm the account you want to sign in with. If the account displayed is the one you want to use for the new company file, select Yes, that’s correct.
• And you’ll be asked to create an Intuit account if you haven't signed in recently. Don't fill this out unless you want to connect your new company file to a new account. Instead, look for the Adding a company to an existing account? section, and select the Sign-in link. Sign in with the user ID and password you already use for QuickBooks

Follow the on-screen instructions to create a new company file. You can also check this article for details: Create or add another company file to QuickBooks Online.

On the other hand, you can move your lists (vendors, customers, inventory, and chart of accounts) from 1/1/24 to your new company so you don't have to start from scratch. Here's how:

1. Sign in to the account that has your lists.
2. Go to Reports.
3. Depending on which list you need to export, search for and run Account List, Customer Contact List, Vendor Contact List, or Product/Service List report.
4. Customize the list report's columns. See the info for each report below to check how their columns should be ordered.
5. Once done exporting, import the data to the new company file.

Keep in mind, that your companies are kept separate for a reason. Changes you make in the future to a list in one company won’t be updated in another company's list.

You might want to update your QBO sign-in info in the future. Feel free to read this article: Update or change your Intuit Account sign-in information.

If you have additional questions about creating a new company file in QBO, click the reply button below. I'll be willing to help. Keep safe and have a good one.

Thank you. We were able to open it. If we have any other issues with it I'll reply with another question. 

Hi there, stevecar.

I'm glad that my colleague was able to help you address or give you information about your concern.

Helping you is our top priority, stevecar. Please get back to us if you need further assistance or have any QuickBooks-related concerns. We're always here to provide you with the assistance and support you need.