Hi jamesfuture4u,
Thanks for your post, and welcome to the community forum! When you shut down your business or cancel the subscription, if you have a desktop or perpetual license, you would be able to access (and record extra transactions) the company file locally and without live services. I highly suggest saving a backup file locally. Once deactivated, you wouldn't be able to access live services, payroll tax tables, and/or other benefits, but you would continue to receive the automatic upgrades to the product. If you do need to install the software on another computer in the future, installers are made available on the Product Downloads page.
Feel free to write a post if you need further assistance.
Cheers,
Jem