Laws passed by the ACT Assembly in August 2013 included a target of reduction from the current total of 5024 to 4000 but a new agreement to be announced by Gaming Minister Joy Burch on Thursday will instead see 4785 machines in operation in 2018.

Ms Burch will unveil a new trading scheme endorsed by Clubs ACT, allowing the sale and purchase of gaming machine licenses as well as reduced operating regulation and more progressive taxation for gambling revenue.

"While I want to see the clubs continue to grow and prosper, this package will also result in the Territory achieving the biggest reduction in gaming machine numbers in history, with future increases linked to population growth," Ms Burch said in a statement.

Based on an adult population of 311,000 in 2016, the government's figures project 4665 gaming machines.

In 2017, there would be 4725 machines in operation.

The territory's current 5024 machines is the highest number per capita of any Australian jurisdiction, but the ACT retains the lowest average revenue per gaming machine.

The changes are subject to amended legislation expected to be implemented early next year. It would see a two-phase process come into effect; during the first three years of the new trading scheme's operation, clubs will be allowed to buy and sell licenses with prices determined by the open market.

Clubs will be required to forfeit one machine for every four traded.

After three years, the new 15 to 1000 adults maximum ratio will come into effect, seeing clubs surrender their license entitlements on a pro-rata basis.

Clubs will have unlimited ability to remove machines from operation and new machine licenses will be released by the government every two years in line with population growth.

From July 1, 2015, the current tax free threshold for gaming machine revenue will be increased from $180,000 to $300,000 per annum and a new tax rate of 23 per cent will apply to revenue above $7.5 million.

Currently the tax rate is 21 per cent over $600,000, but the government believes the changes won't adversely impact its revenue base.

Hotels and taverns will no longer be able to apply for class B licenses, which include draw poker and keno machines, but existing businesses will have the option of continuing to operate their machines or sell entitlements to clubs as part of the trading scheme.

Small clubs will be able to pay their contributions to a problem gambling fund on an annual basis, retrospectively.

"The ACT Government is committed to ensuring that our clubs are supported by contemporary regulatory arrangements so they can continue to thrive," Ms Burch said.

"It has been important to strike a balance between reforms that help our clubs with harm minimisation and the revenue impact on government. It is a mark of the strength and maturity of ACT clubs that they have been able to work through these issues and agree to a package that will help secure the sector's long-term future."

Clubs ACT chief executive Jeff House said the agreement would allow the industry greater certainty for commercial decisions.

"The reform package is balanced and deals with issues which have been on the respective agendas of government and the club sector for some time and meets several of the commitments contained in the Memorandum of Understanding that exists between ClubsACT and the ACT Government.

"It is generally acknowledged that clubs are doing it very tough at the moment and it is disappointing that the modest tax relief included in the package for smaller clubs comes at the expense of larger clubs."

The organisation had argued the target of 4000 machines was too severe.

The changes will also give clubs access to lease variation charge remissions when redeveloping their land and an upcoming round table event will discuss other ways the government can support clubs in their efforts to diversify operations.

License holders will have increase ability to move machines, the existing gaming machine access register will be abolished and machine attendants will no longer need to be approved for work.

Both the government and clubs will work to find ways to improve social impact assessment processes without reducing harm minimisation arrangements.

In 2012, the ACT Auditor-General said Canberra had nearly 16,000 problem gamblers or people exhibiting symptoms of problem gambling.