The ACT's business confidence rating went up two percentage points to +54 in the Sensis Business Index survey for the March quarter, with an increase in sales the driving factor.

But the biggest growth came in business support for the territory government, which rose 21 percentage points to +9 on the index.

Sensis chief executive John Allan said an increase in infrastructure spending and the perception of a supportive government was behind the wave of support.

Canberra Business Chamber chief executive Robyn Hendry said with the ACT government now in the second year of its four-year cycle, there was more certainty for businesses.

"In its first year, the government is still implementing a lot of its policies, but by the second year, businesses know more about where the government is at," Ms Hendry said.

"Business confidence and certainty go hand in hand, and business really likes certainty."

Ms Hendry said alongside an increase in sales, higher export numbers and the strong growth of industries like tourism, which added 1100 jobs last year, had businesses feeling more confident.

The ACT faced some challenges though, she said, including the cost of workers' compensation and the impact of rates increases.

"We're also always competing for talent, and some of the feedback we're getting is that while the education system is strong, what people are lacking is real life skills," Ms Hendry said.

"Businesses want more work-integrated programs to increase graduates' value. We also need to ensure that the people who are studying here are aware of the career opportunities available in Canberra, so that they stay here."

Despite the boost this quarter, business confidence in the ACT is still down 10 percentage points on the same time last year, when it was +64 on the Sensis index.

Ms Hendry said people shouldn't read too much into that drop, with the March 2017 results coming after a long period of uncertainty that included the 2016 ACT and federal elections.

"The [business confidence rating] bobs up and down, and elections create no end of uncertainty," she said.

While the ACT government's popularity surged by 21 percentage points in the latest Sensis survey, support for the federal government rose just two points to a neutral position.

The survey, which reflects the view of 1000 small and medium-sized Australian businesses, shows businesses in the ACT and Tasmania share the most positive outlook at +54 on the index.

The national average of +42 remains unchanged from the last quarterly survey, conducted in December.