Firstly: already-installed software can be used forever, whether you have access to updates or not.
With each purchase, access to personal support and updates to install/update to new releases of UpdraftPlus is for 12 months. (As is the case with about 90% of the premium WordPress plugin market).
After 12 months, you can renew your access with very generous discounts.
To repeat: if you prefer not to renew, then your installed software is unaffected – it will remain installed and you can carry on using it.
Posted in: General and pre-sales questions