ACT Compulsory Third Party regulator representative Karen Doran approved the increase, the first by NRMA in more than two years.

Third party insurance laws require licensed insurers operating in the territory to charge premiums to fully fund present and future liabilities, but which are not excessive.

Ms Doran said approvals of new premiums follow an extensive actuarial review process.

NRMA had a monopoly on third party insurance in the ACT until July 2013, but now competes for customers with Suncorp's GIO, AAMI and APIA.

"The new premium for a family car insured by NRMA will be $588.60 – a small increase of $10.40 or 1.8 per cent from the current premium of $578.20," Ms Doran said in a statement.

"This is NRMA's first increase since September 2012.

"Based on independent actuarial advice, I am satisfied that NRMA's new premiums are soundly based and are not excessive."

In 2012, NRMA Insurance's third party premiums rose by about $52 to $578.20.

Premiums for third party insurance are subject to ACT government regulation, in order to compensate people injured in car accidents and to ensure prices are kept to appropriate levels. The fees are paid entirely to licensed insurers and not to the government.

Third party premium levels are set based on past claims and projections of the likely number and cost of claims in the future.

The premium charged depends on the type of vehicle and whether it is used for private purposes or for business purposes.

Under the new NRMA premium categories, all third party premiums will increase by between 1.7 per cent and 2.1 per cent. Rates for commercial goods vehicles will increase between by up to 2.1 per cent.

Goods vehicles under 4.5 tonnes will be see premiums rise to $673.10, while those over 4.5 tonnes will increase to $2454.90.

Hire car premiums will increase 1.8 per cent to $2354.40 and motorcycle premiums will increase to between $117.70 and $529.70 depending on the engine size.

Taxi vehicle premiums will increase 1.8 per cent to $8829.