If you're using QuickBooks Online Essentials, Plus, and Advanced, you can purge your data as long as your account is less than 60 days old. The system deletes all data entered into the company, and you're unable to restore or reverse them.
To purge your data:
Log in to your QuickBooks Online account.
Change the URL to include /purgecompany.
Example: URL shows https://...qbo.intuit.com/app/homepage, change to https://...qbo.intuit.com/app/purgecompany.
The next screen will provide a summary of the items to be deleted.
Type the word “YES” once the data gets deleted, then click OK.
Click Wipe Data once your selections are complete.
Once the deletion is complete, you will be rerouted to your home page.
On the other hand, if your account is 60 days old or older, you need to cancel your account and start a new subscription.
Here's how to cancel your account:
Go to Gear icon and select Account and Settings under Your Company.
Select the Billing and subscription tab.
In the QuickBooks section, select Cancel.
Follow the steps to cancel your account. If you use payroll, you should cancel your payroll account too.