We're sad to let go of an important subscriber like you, @noiprotection-gm. However, if this is due to the needs of your growing business, you can cancel your QuickBooks Online (QBO) account easily through the Billing & Subscription menu. I'm here to guide you how.
Before we start, I'd recommend saving and/or exporting all the necessary reports, transactions, and important account data. This is to make sure you have a reference for future use.
Whenever you're ready to cancel, here's how:
Open a web browser on your computer and sign in to QuickBooks Online as an admin user.
Go to the Gear icon.
Select Account and settings.
Go to the Billing & Subscription menu.
In the QuickBooks section, select Cancel subscription or Cancel online. If you're canceling a trial, select Cancel trial.
Follow the onscreen steps to complete the process.
I've attached a screenshot below that shows the fourth and fifth steps.
Once completed, your account will totally be cancelled and charges will automatically be stopped. You'll be given a year of read-only access to your QuickBooks data after the process. If you wish to know more about file availability and export policies after cancellation, I'd recommend checking out this article: What happens to my QuickBooks Online data after I cancel?.
Let me know in the comments below if you need further assistance in managing your QBO account. Take care and stay safe always.