The option to purge a company data is only available if your books are less than 60 days old. Beyond the 60 days period, you will need to cancel your QuickBooks account. Then, start signing up for a new company.
Enter your user ID and password. You can use the same user ID and password you used before.
Optional: If you use payroll, sign up for payroll again in the Payroll menu.
For canceling the old account, you can follow the steps below. Before doing so, please check the Learn what happens to your data after you cancel section in this article: Cancel your QuickBooks Online subscription or trial.
Go to the Gear > Account and settings.
On the left panel, click the Billing & Subscription tab.
Select Cancel subscription.
Follow the steps to cancel your account. If you use payroll, you should cancel your payroll account too.
If you have more questions regarding the process or need help with other features in your account, please let me know in your reply below. I'll be right here to answer them. Have a good day ahead!