"Fuller House" star Elias Harger might only be 9 but little dude's already inking his contracts with his 4th grade cursive and John Hancock.

Elias plays DJ's -- aka Candace Cameron -- son on the rebooted series. He earned $10k an episode for the first season, a little more than his on-screen younger brothers. Not bad for a 9-year-old.

Elias was in all 26 episodes from the first two seasons and got a $400 raise per episode for season 2 ... so, yeah, the kid's got college tuition covered. 

As for season three, Elias is going to be making $10,816 an episode! No wonder the kiddo's got his signature down pat.