Submissions to an inquiry tackling the territory's heraldry have been opened to the public until April 21, and should address whether the ACT should adopt one at all, and what it might look like.

The ACT is the only state or territory in Australia, and one of few jurisdictions in the world, without a coat of arms, while Canberra city's - which hangs over the assembly - is mostly "irrelevant" to locals.

"It's a topic that a group of people in the community feel very passionate about but it's also a topic that other people will, when asked, have an opinion on," chair of the inquiry's committee Suzanne Orr said.

Since the inquiry was referred to the standing committee on environment, transport, and city services in November 2018, many people have rung in to share their opinion on the issue, Ms Orr said.

Submissions weren't invited until later because of the unique nature of the task at hand. Some submissions had already been sent in and an online survey in May would allow more people to contribute "with a few clicks".

"It's such a unique thing to adopt a coat of arms. It has not been done since the 1970s and that was the Northern Territory, so we weren't quite sure what the process was and what the parameters were," Ms Orr said.

A report would be handed up to the assembly by the middle of the year and it would ultimately be a government decision as to whether or not a new coat of arms was adopted. The ACT's flag, which features Canberra's coat of arms, would likely have to be changed too.

While Canberra's coat of arms has some connection to the national capital, it first being used in 1928 on an Australian warship, HMAS Canberra, it was "right out of kilter" with locals today, republican Terry Fewtrell said.

"It is full of British symbolism, except for the swans perhaps," he said.

"In terms of symbols that speak for us authentically, I think they come from either the land or the values of the people, and to some extent our Indigenous people and the heritage there we are so fortunate to have.

"To me, some representation of the Brindabellas would be a good thing. It would speak of our place because we live our lives against their backdrop."

Although Mr Fewtrell initially campaigned for Canberra's coat of arms to be replaced entirely, it would be too difficult to do in practice, he said. Having one for the territory would be a good compromise.

"I would urge people to put in a submission and express their view on these things and this is an unusual opportunity that we have to rectify a historical anomaly that we don't have an ACT coat of arms," he said.

"It’s a chance for us all to participate in that process and have something that really does speak of us and the place in which we live."