The number of public telephones across the region has more than halved in the past decade, leaving just 50 such phones in operation between Helensburgh and Gerringong.

In 2005, the Illawarra was home to 117 public phones. Last year, that number dropped to just 52.

In the majority of the region's northern suburbs and towns further south, residents have access to a single payphone, usually located near the train line.

Wollongong CBD boasts the most public phones at 10, but many are found in the Crown Street Mall or near the railway station.

Even bigger suburbs like Port Kembla and Unanderra have just three phones each.

Warrawong Residents Forum manager Maxyne Graham hands out about 50 Telstra payphone vouchers a month to people visiting the Warrawong Community Centre.

She said her six-month supply of vouchers often ran out, showing many people were still reliant on public phones.

"People use them to phone Centrelink, to find housing, to contact Corrective Services or to phone doctors; there's definitely a need for them," she said.

"Quite often they don't have mobile phones, they can't afford them, so they rely on the public phone boxes."

Ms Graham said clients had commented on the demise of phone booths, noticing many had disappeared from their area.

"We have people coming in, especially in the outer suburbs, saying they don't have a payphone on their street," she said.

"We're lucky in Warrawong that we have a couple but many suburbs only have one."

The decline across the Illawarra is in line with an overall nationwide fall in public phones, from almost 70,000 10 years ago to fewer than 30,000 last year.

In the early 1990s, before mobile phones changed the way people communicate, there were more than 80,000 payphones across the country.

A Telstra spokesman said revenue from payphones had declined 70 per cent since 2008.

But payphones are not in danger of becoming extinct.

Last year, Telstra signed a 20-year contract with the government, worth $40 million annually, to maintain its remaining payphones.