The NDIS won't fund Billy's car modifications until he has a licence. He needs them to take the test.

Like most 20-year-olds, Billy wants the independence that comes with having a licence.

He's dedicated the last two years to getting his driving hours up so he can qualify for his Ps.

"I take it very seriously, I am very cautious on the roads. I watch out for every hazard," Billy said.

Billy lives with a rare and painful genetic disorder called epidermolysis bullosa.

It means he has incredibly delicate skin and even a simple tap can cause his skin to tear.

"I can't shower by myself, I can't really cook, I can't wash my clothes," he explained.

Billy uses a special glove to operate the steering wheel, but he needs help with the gears and door handle.

"My hands are basically a fist, I can't open them up. I can't grip the steering wheel, I can't change gears," Billy said.

He says the NDIS confirmed it would fund modifications to his car, including buttons to change gears instead of a stick.

But when Billy was ready for his test, the disability support service allegedly backflipped.

While it was first expected Billy would receive the modifications before his driving test, he was then told the licence had to come first.

"There was a point when they declined him that he just said, 'Mum, I don't want to do this anymore. I just, I'm not going to drive. I'm going to accept that I will never drive'," Billy's mum Rebecca said.

"As a mother, that was heartbreaking."

Billy says his independence isn't being stopped by his condition - it's being stopped by the NDIS.

"I want to just drive. Everyone drives. That's my goal," Billy said.

Since contacting the NDIA regarding Billy's situation, the scheme has taken another look and agreed to fund the vital vehicle modifications so Billy can take his test.

FULL NDIA STATEMENT

"The NDIS can provide funding to assist participants to have the freedom to get where they need to go, including modifications to a participant's vehicle.

Each request for vehicle modifications is assessed by specialist staff, and decisions made in line with the NDIS Act 2013.

The NDIA continues to work closely with Mr O'Brien regarding his NDIS support needs."