Monday brings a return to lesson's for NSW students and a subsequent resumption of school zone speed limit enforcement.

Drivers who speed through school zones face hefty fines.

Exceeding the speed limit in a school zone will set drivers back $189 and two demerit points, but go over the limit by more than 45 kilometres and the penalty is seven demerit points, a $2530 fine and a mandatory six months disqualification from driving.

Any motorist caught using a mobile phone in a school zone, the penalty is $439 and four demerit points.

Disobeying a 'no stopping sign' in a school zone will attract a $330 fine and two demerit points.

For all the rules around school zones click here.