Subsidies to make vans wheelchair accessible are no longer economically viable for taxi companies.

Christchurch wheelchair users have voiced their frustration over a lack of availability of accessible taxis, due to them being used by able-bodied passengers.

Melissa from Christchurch, who has a motorised wheelchair, was left waiting at the airport because the van she booked didn't have a driver who was wheelchair accredited and was picking up other patrons instead.

"Wouldn't they have some rules around that, like you have to supply a driver for every shift in this vehicle. That doesn't seem to happening. In my mind, that seems like quite a simple fix".

She said after a lengthy delay she had to be picked up by another company, only to find out there was a van available, but the driver wasn't wheelchair accredited.

Melissa said it's been an ongoing issue, as there isn't enough people in chairs to maintain the ongoing costs.

Through the total mobility scheme, taxi companies have a contract with ECAN to have equipment in their vans subsidised so they can offer services to wheelchair users.

Taxi Federation executive director Roger Heale said the subsidy isn't enough and companies are having to take on other passengers to cover the costs.

He said sometimes the gap between the subsidy and the actual cost of the van is as much as $20,000.

Heale said the wheelchair vans often double as a passenger van just to make them economically viable.