I'm glad you are interested in using QuickBooks Online again, @Trimu.
If you cancel your QuickBooks Online account, you will retain read-only access to your data for one year provided that you have only one account.
After a year, your data will be deleted. That is the reason why the system cannot find your account.
To use QuickBooks Online again, start a new subscription and add a new company.
You can click this link for a new subscription and see available promotions: Plans and pricing.
For future reference, here is an article you can read to help you get started with QuickBooks Online: Get started and adjust settings after you sign up for QuickBooks Online.
Let me know if you have questions about resubscribing in QuickBooks Online. I'm always here to help. Have a great day.
