Would you trust a stranger with your bank PIN? It's a question Nadia Mattiazzo is forced to ask herself daily.

Key points: Commonwealth Bank facing lawsuit alleging discrimination over touchscreen EFTPOS machines

Commonwealth Bank facing lawsuit alleging discrimination over touchscreen EFTPOS machines Blind and vision-impaired people say terminals are virtually impossible for them to use because they don't have tactile keypad

Blind and vision-impaired people say terminals are virtually impossible for them to use because they don't have tactile keypad Lawsuit follows 18 months of unsuccessful negotiations with the bank

Ms Mattiazzo is blind and relies on her guide dog, Olympia, to navigate through parts of everyday life.

But now, even a simple trip to the shops or a local cafe fills her with anxiety.

Since the introduction of the Commonwealth Bank's "Albert" EFTPOS machine more than two years ago, Ms Mattiazzo said she felt vulnerable while paying for purchases.

There are more than 88,000 Albert machines across Australia and they are entirely touchscreen.

A PIN needs to be entered for purchases of $100 or more on payWave cards.

Blind and vision-impaired users say the terminals are virtually impossible for them to use because they don't have a tactile keypad.

For Ms Mattiazzo, the machines demonstrate how some parts of society are still out-of-touch with people with special needs.

"Today's world is becoming more accessible to people with disabilities — the technology is already there," she said.

"I can hold down a job because my computer is accessible, I can withdraw cash from an ATM because my bank has keypads on their machines. But I can't buy a coffee."

Ms Mattiazzo said, at times, she has been forced to give her PIN to cashiers to process a payment on her behalf. This breaches the terms and conditions of her contract with her bank, and leaves her feeling vulnerable.

"In situations where you've ordered something and the item has been prepared, unless I'm prepared to walk out of the business and make a scene by doing that, what do I do?" she asked.

Albert machines 'a bad design they need to fix'

Ms Mattiazzo has joined forces with former Disability Discrimination Commissioner Graeme Innes and has lodged a lawsuit against the Commonwealth Bank, alleging discrimination.

There are more than 88,000 of the Albert machines across Australia. ( ABC News: Andy Ware )

"In today's day and age … accessibility is so important and is being considered in so many areas," she said.

"We have ramps into buildings, we have accessible technology, we have iPhones, which have an absolute accessibility feature built into them. It's really disappointing to know that there are things being developed that don't have that consideration."

The Public Interest Advocacy Centre (PIAC) is representing Nadia Mattaizzo in the case, which will be heard in the Federal Circuit Court.

The group's CEO, Jonathan Hunyor, said the Albert machines prevented vision-impaired and blind users from conducting transactions safely.

"Often technologies are introduced without the question being asked: can it be used by everyone in our community?" Mr Hunyor said.

"Often accessibility is an afterthought. And that's the problem we're having here, where we say the Commonwealth Bank hasn't got the design right from the beginning, and that makes it a bad design that they need to fix."

Vision-impaired users 'can listen to PIN instructions'

The lawsuit follows 18 months of unsuccessful negotiations with the Commonwealth Bank over the machines after a complaint to the Human Rights Commission by advocacy group Blind Citizens Australia and PIAC.

In a statement, a Commonwealth Bank spokesperson said it worked "collaboratively with both our technology partners, accessibility specialists and individuals with a range of vision loss to deliver the current accessibility".

The spokesperson added the Albert machine contained an accessibility feature that enabled vision-impaired users to listen to instructions to enter their PIN.

However, chief executive of Blind Citizens Australia, Emma Bennison, who is blind, said the feature was often unhelpful to vision-impaired users.

Emma Bennison says many users are forced to give their PIN to friends or cashiers. ( ABC News: Sarah Farnsworth )

"It's terribly anxiety provoking," she said.

"I was in a coffee shop the other day, holding up the queue trying to enter my PIN and I found it incredibly distressing because the people behind me didn't know what I was doing, all they saw was me struggling to pay my bill.

"They probably thought that I didn't have enough money, but in fact I was trying to listen to this tutorial just so I could enter my PIN. It's just ridiculous."

Ms Bennison said many users were forced to give their PIN to friends or cashiers to complete a transaction after unsuccessfully trying to follow the accessibility tutorial.

"Imagine what it would be like for a sighted person to take the numbers off a device and asking them to enter their PIN. That's what it's like for people who are blind or vision-impaired," she said.

"I think it makes people firstly, very anxious when they're having to hold up a queue listening to a tutorial that tells them how to do something that last week they could do with a device with a keypad.

"Now they have to listen to this tutorial, hold up a queue, and then in many cases find that they still can't enter their PIN."