Homelessness services are reporting a rise in clients who are elderly women, some resorting to sleeping in cars and couch surfing for shelter before seeking help.

Rising rental prices in areas previously more accessible for low-income groups and pensioners have locked out older women with low superannuation and savings.

YWCA Canberra executive director Frances Crimmins said the housing options for elderly women were "dire".

"There were more options for affordable rental accommodation in surrounding regions, but even that's evaporated in terms of affordability," she said.

She has seen cases of women as old as 70 living in their cars and couch surfing to avoid rough sleeping or contacting homeless services.

In Canberra, 316 people aged 55 years or older sought help from homelessness services last year and 44 per cent in this group were women, according to the Australian Institute of Health and Welfare. Of all homeless clients, 6.8 per cent were aged more than 55.

Within this age group, 79 clients were aged 65 or older.

Support service Toora Women's executive director Susan Clarke-Lindfield said since 2015, 25 per cent of its residential clients and 37 per cent of outreach clients had been more than 45 years of age.

"The change has been that we are now seeing more women in their late 60s, 70s and 80s coming through."

Homelessness figures reflect reports from services seeing an increase in older clients. Since 2011-2012, the number of homeless people aged more than 55 has grown by 9.5 per cent each year. Their number is growing at twice the rate of the general homeless population.

Council on the Ageing ACT spokeswoman Catherine Adcock described homelessness among elderly people, particularly women, as an emerging problem.

"There's a trend there where more people are accessing homelessness services," she said.

Older men were also increasingly seeking help about unstable housing, and those struggling with homelessness had outstripped population growth, ACT Shelter executive officer Travis Gilbert said.

Women were entering retirement with less money to afford housing costs, making them vulnerable to homelessness if family violence forced them out of home, services reported.

Lacking a home to sell made entry into aged care harder, Mr Gilbert said.

"It's really a precarious situation to be in, if you're living in the private market and living on an old age pension."

Job opportunities for women more than 55 years old were also lacking, Ms Clarke-Lindfield said.

"They ... cannot afford private rental or shared accommodation because it would cost more than 50 per cent of their pension," she said.

"When coming from domestic violence situations, many older women have joint assets to which they have no access. There are a number of legal hoops and housing eligibility processes to go through before they can be independently housed."

Of 175 women seeking homelessness support from the YWCA last financial year, 55 named family violence as the main reason for leaving home.

Queanbeyan-based anti-homelessness advocate Penny Leemhuis said there was a bottleneck at shelters for women.

YWCA's affordable housing tenancies for older women are full.

ACT Housing Minister Yvette Berry said the government would address housing costs by continuing to phase out stamp duty and restructuring the Land Development Agency to focus on affordable and efficient greenfield land release.

She said the government's Affordable Rental Scheme provided housing for older people on low incomes, operating through a tiered rent system that charged a percentage of market rent.

The ACT Government has committed to developing a new affordable housing strategy and holding a homelessness summit.

The government's parliamentary agreement identifies older women as a vulnerable group, along with women escaping violence.

"The new ACT Affordable Housing Strategy will work to deliver improved housing outcomes for these groups," Ms Berry said.

Specific services for women, including older women, included up to 92 accommodation places and 176 support places, she said.

The ACT's specialist homelessness sector performed well compared to other jurisdictions, with the highest proportion of clients receiving support for their tenancies, Ms Berry said.

However a Productivity Commission report released in January found homelessness services were unable to provide housing to more than one third of clients in the ACT last year as spending on the sector dropped.

The ACT also recorded the highest percentage of clients experiencing repeat periods of homelessness, at 7.9 per cent, larger than the 5.6 per cent national average.

Funding for homelessness services dropped from $24.8 million in 2012-2013 to $20.1 million in 2015-2016, in real terms, for the ACT.

Assistant Social Services Minister Zed Seselja said the federal government provided states and territories with $1.3 billion a year through the National Affordable Housing Agreement, which included about $275 million for homelessness services.

Under the 2015-17 National Partnership Agreement on Homelessness, the government provided $115 million each year to fund frontline homelessness services.