I know for the likes of a car, your provisional will do you for 3 years or something before expiring. What is the timeframe with lorry provisional?
I think that depends on a few things mate ie medical ect i can tell you that your theory test pass certificate only last two yrs if you dont pass practical in that time you have to re do the theory again 
LGV should be valid to 45, the car until you’re 70.
The medical will last for a least 5 years or age 45 - whichever is the LATER of the two
HPT and theory will only last two years from pass date
I think it’s five years for C, & D provisinal, you may be able to confirm that on DSA website 
, then you’ll know for sure 