The Hunter Valley bus driver who was sentenced to 32 years' jail for causing a crash that killed 10 people has begun the process to appeal his prison term.

Brett Andrew Button, 59, was sentenced to a  maximum 32-year term with a non-parole of 24 years on Wednesday.

Button was driving wedding guests from the Hunter Valley vineyards to Singleton on June 11 last year when the bus rolled and hit a guard rail at Greta.

In Newcastle District Court this week Judge Roy Ellis deemed the case unprecedented in terms of the number of people killed, along with the 25 injured.

The court of Criminal Appeal has told the ABC a notice of intention to appeal was lodged on Friday afternoon.

No dates have been set for the appeal proceedings.