The ACT has used subtle psychological cues to encourage ratepayers to pay up sooner.

The Government enlisted an Australian National University researcher to conduct “behavioural insights” trials on billing templates, according to notes prepared for Chief Minister Andrew Barr.

The research informed “the redesign of a number of tax forms and correspondence”, including a new-look land rates notice.

The new land rates notice was issued last year, after the Government scrapped a discount for those who pay their yearly rates upfront.

The bill included a large box that said “pay now” with the full year's rates cost, leading many to believe they had to pay the entire bill in a single instalment, rather than quarterly.

The rates notice was redesigned to take advantage of the experiment's findings and bring in more money, the Chief Minister's briefing notes say.

“While [the behavioural insights program's] impacts appear small, they are extremely cost effective,” the briefing notes said.

“The benefit-to-cost ratio was estimated at … approximately 8.7 for the best performing variant.”

The Government has since agreed to review the design, but denies that the notice aimed to prompt more upfront payments.

“The clearer rates notices now include more information to improve the payment process and reduce the amount of late payments and unpaid notices,” the Government said in a statement.

“We will continue to look into the best ways to provide information to the community.”

Opposition Leader Alistair Coe said it was “misleading”.

“I think it was misleading… It clearly said that the full amount was payable, when in reality only a quarter of it was payable at that time, and so it did cause considerable distress,” Mr Coe said.