@Flyingkiwi 

If you are using QBD UK version with the one time license, you can keep it that way for the time being. You can still purchase QBD 2020 UK version with the one time license from several partners if required.

You can purchase a 3rd party service to convert data from QBD UK version to QBD US version.

You can still purchase QBD 2021 US Pro/Premier or QBD 2022 US Premier Accountant with the one time license.