Thank you for joining the thread, @thatch.

The steps provided above (click the File menu) is for the QuickBooks Desktop version. If you're using QuickBooks Online (QBO), you can either delete or purge your company file to start fresh for January 2020. If your QBO data is less than 60 days, you have the option to purge your account if you're using QuickBooks Online Plus, Essentials and Advanced. The system deletes all data entered into the company, and you're unable to restore or reverse them.

To purge the data, follow the steps listed below:

1. Log in to your QuickBooks Online account.
2. Change the URL to include /purgecompany.
3. Example: URL shows https://...qbo.intuit.com/app/homepage, change to: https://...qbo.intuit.com/app/purgecompany.
4. The next screen will provide a summary of the items to be deleted.
5. Type the word “YES” once the data gets deleted, then click OK.
6. Click Wipe Data once your selections are complete.
7. Once the deletion is complete, you will be rerouted to your home page.

If it's 60 days old or older, you need to cancel your account and start a new subscription.

To cancel your account:

1. Go to Gear icon and select Account and Settings under Your Company.
2. Select the Billing and subscription tab.
3. In the QuickBooks section, select Cancel.
4. Follow the on-screen instructions to cancel your account. If you use payroll, you should cancel your payroll account too.

To start a new account:

1. Go to https://quickbooks.intuit.com/choose-country/.
2. Fill up the User ID and password.
3. You can use the same user ID and a password you previously had. If you activated payroll in the account, this is the best option for you.

Here's an article you can read to learn more about this process:  Delete your data and start over in QuickBooks Online.

As you continue working with QuickBooks, you can also read the topics from our help articles as your future references.

Post again if you have any other questions. I'm a few clicks away to help. Keep safe always!