I added additonal words in bracket to make it right, according to my knowledge. 1.It was not until [he was] thirty years of age that he got his driving licence. 2. It was not until he was thirty years old that he got his driving licence.- nothing wrong here 3. It was [at the age of] thirty years of age that he got his driving licence. my version: He was thirty years old when he got his license,

2. It was not until he was thirty years old that he got his driving licence. *license* "It was not until his thirtieth year that he got his driver's license", could be correct, but it's extremely formal and literary. No one speaks like that, and you'd only read it in a (slightly) old-fashioned book. Examples: I'm thirty years old, and my sister is twenty-five. My dog is four years old, my cat is ten. That store has been on the corner for a hundred years. I remember going there when I was a child, and I'm 80 years old.

Only 2 is correct. The simplest, colloquial way to say it is "He didn't get his driving licence until he was thirty".

This answer : It was not time until his thirtyth years that he got his driving licence