With average gas bills rising in the ACT from between $833 and $881 in 2012-13 to a whopping $1481 to $1688 in 2015-16, so too have related debts.

The Australian Energy Regulator's March quarter performance data shows Canberra households had the highest gas debts and second-highest electricity debts of all five jurisdictions on the market.

That was before the estimated increase of $333 for residential electricity bills and $247 to gas bills started in July.

The situation has created a "double whammy" for Canberra's lowest-income households, some of whom are simply stopping using gas altogether to avoid the bills piling up, ACT Council of Social Services' Susan Helyer says.

Ms Helyer said financial counsellors in Canberra had been regularly hearing of cases where low-income households, struggling to pay their bills, had simply stopped using gas for heating, to avoid consumption charges.

While the territory government increased concessions in response to community concerns in July this year, it has also begun a review of the concessions system, to find out if it is working well enough or should be more targeted.

The AER data shows the average gas bill debt in the ACT in the March quarter hit $654, compared to $536 in NSW and around $360 each in SA and Queensland, while electricity bill debt hit $870 in the ACT, exceeded only by SA's $875 average debt.

In the ACT, average residential gas debts have risen from $441 in September 2012 to $654 in March this year, while the same debts for electricity bills rose from $680 to $870 in the same period

The data also shows the ACT had the highest rate of gas bill debts in the jurisdictions measured, at 4.7 households for every 100 with a gas bill debt, or 5601 Canberra households facing that situation.

Ms Helyer said the situation was "very worrying" because the AER data came from March, a quarter traditionally linked to lower bills due to lower consumption.

She said financial counsellors had also received a "peak in demand for assistance" in July this year, earlier than previous years and she expected the trend would continue.

"The households that are struggling are in a worse financial circumstance than those households in other jurisdictions, mainly due to the relatively high cost of living in this city, combined with the high need to use energy," she said.

"It's causing a double whammy in this city, particularly for renters, where they are paying comparable rents to other jurisdictions, but they have relatively high energy costs, because most low-cost housing has poor energy efficiency and a lot of rental properties are reliant on gas for their heating."

Ms Helyer said while she understood the territory government was considering expanding concessions for some households, the long-standing problems around federal energy policy was "much bigger" than a territory issue.

"What we know is that low income households are at the cutting edge of the failures in those policy settings," she said.

"What we've been arguing is that concessions should be based on level of income, not the source of the income.

"It's no longer true that having a job means you're not financially stressed, especially for those in casual or without steady hours of work."