Canberra commuters will pay more to ride on ACTION buses from next month.

From February 4 the fares will increase by 5 per cent and MyWay cards will cost $5 instead of being free.

Concession holders will pay half the cost of full bus fares and MyWay cards.

It is the first increase in bus fares since July 2010.

The ACT Government says the changes reflect the rising cost of operation and improvements to public transport.

Changes to monthly trip caps mean passengers will have to pay for an extra four rides before they receive free travel.

The body representing Canberra's low-income earners has warned the increase will unfairly target the already disadvantaged.

Kiki Korpinen from the ACT Council of Social Service (ACTCOSS) says up to 20 cents a trip might sound like a small amount, but it is not for everyone.

"We are concerned with increases in public transport fares, as these increases may place a significant burden on low-incomer earners who are reliant on public transport as their only means of travel and are most affected by increased changes to transport fares," he said.

Most ACT public school students will return to classes on Monday February 4, the same day bus fares will increase.