Fine revenue has also fallen from almost $205,000 last financial year to about $81,000 so far this financial year as people do more to avoid getting pinged for overdue items.

An increase in fines was also likely in the new financial year.

All fine money is returned for use in the libraries. The way the fines were tracking, this financial year's were likely to be about $160,000, $45,000 less than the previous year.

Libraries ACT director Vanessa Little said the reduction in fine revenue was not a worry.

"The fine is not about the money generation, it's about changing behaviour. And we just want our material back so that we can give it to the next person," she said.

Ms Little said since the new fine system was introduced in March last year, the number of overdue items had fallen.

"Under the previous system we had, about 10 per cent of all loans were overdue. We've dropped down to 5 per cent," she said.

"We do 3 million loans a year so 5 per cent is pretty good."

In March last year, fines for overdue items went up to 25 cents per item per day, with a maximum cap of $7 per item. The previous fine was 20 cents per item per day.

Once items were overdue for a month onwards, members were suspended from borrowing.

If an item was lost – deemed to be so if overdue from 30 days onwards – the member was liable to pay its replacement cost and a $6 administration fee.

Ms Little said the fines were working.

"It's certainly achieved what we hoped," she said.

The fines were likely to increase in the new financial year, probably to 30 cents per item per day, pending government approval.

"At some point they will go up but it won't be anything massive. We're not going to send it up to 50 cents or a dollar or anything like that," Ms Little said.

Pensioners were also fined for the first time under the new system.

"Some of the pensioners have made comments about it but overall most people have see the fairness in it and they get their stuff back on time or they extend it," she said.

"You can extend it online or by ringing us or by coming in to see us at the library."

Ms Little said she did recognise that parents who routinely borrowed multiple items, such as picture books and DVDs, for their children might be more prone to racking up higher fees than other users who might borrow only one thing as a time.

"It's a constant juggle for people," she said.

"We do send out a courtesy email (listing due items) which we find helps parents particularly because then they've got a list of items to go looking for."

Ms Little said the number of lost items had not increased or reduced significantly.

"Sometimes, you know, dogs eat books. I have had that happen to me. I had to go to the library and say, 'My dog ate my book'," she said.

"You know kids do all sorts of things. People leave books on buses. Sometimes they make their way back to us. People find books on a bus and send it back to us. Our loss rate through people damaging or losing stuff is not high.

"At 30 days [overdue], we assume you've lost the item. So we send you a nice little letter that says, 'The book was worth this amount and the processing fee is this' and it's amazing how many people find that book."