Once your QuickBooks Online subscription has been canceled, we will keep your data for a year. Within that period, you'll have read-only access to it but you can export the data for future use.
After that, your account and its data will be deleted automatically.
If you haven't canceled it yet, please follow these steps:
Go to the Gear and select Account and settings.
From the Billing & Subscription tab, select Cancel subscription or Cancel online.
Follow the onscreen steps.
Please note that within the one-year period, you can still resubscribe and reactivate and your data won't be deleted.
Shoot me a reply if you have further concerns with your subscription. I'll help you!