The MTR Corp will earn HK$200 million from a 2.2 per cent fare increase to take effect on June 19.
But the corporation says nearly 80 per cent of its passengers will pay no more than 20 cents extra for a ride.
The increase will coincide with a series of discounts and promotions that the corporation said would cost HK$1.7 billion.
'Fares for 79 per cent of all passenger trips will change by no more than 20 cents, including six per cent not experiencing any fare increase at all,' MTR general manager of marketing Jeny Yeung Mei-chun said.
For other trips, fares will rise by no more than 30 to 50 cents.
One of the biggest fare increases will be for a trip from Wan Chai to Yuen Long, which will cost HK$22.90 by Octopus or HK$24.50 by single-journey ticket, compared with HK$22.40 and HK$24 at present.
Octopus users normally pay less than people buying tickets from vending machines. But under the new fares, smartcard users will pay 10 cents to 20 cents more than single-journey ticketholders on about 30 trips, such as Kowloon to Sha Tin.
The corporation said this was because the new single journey fares were rounded off to the next 50 cents while Octopus fares were being rounded off to the next 10 cents.
As the rounding off might mean an excessive charge for some of its shorter, cheaper journeys, the corporation has waived the increase for such trips on single-journey tickets. This means that these journeys will become more expensive for passengers using an Octopus card.
The operator said the trips involved were fewer than those under its fare rise last year, when 100 of its 40,000 journeys or fare combinations were affected.
New promotions include one offering a single-journey ticket to anywhere on the MTR domestic network to adult Octopus cardholders who spend HK$100 on MTR fares from Monday to Friday in one week. The 'Ride $100 for Free Ticket' promotion will run from July 4 to December 30.
New interchange discounts with five outlying island ferry routes and three green-top minibus routes in Kwun Tong as well as enhanced discounts in Tung Chung will also be introduced later this year.
All these promotional discounts will be worth HK$1.7 billion. The company's net profit last year was HK$12.06 billion.