Designed to discourage people from travelling on trains without first paying for their tickets, the penalty fares will be implemented on five selected routes from next week.
The penalties, which will be Â£20 fines or double the cost of a single fare (whichever is the greater), will be enforced at destination stations by Northern’s authorised collectors.
Previously trialled in West Yorkshire, the scheme is in the process of being rolled out more widely across Northern's network.
It will be introduced on the following routes from next week: Blackpool stations to Liverpool (via Preston, Wigan and St Helens); Preston to Manchester (via Buckshaw Parkway, Bolton and Salford); Wigan Wallgate to Manchester (via Hag Fold and Swinton); Manchester to Leeds (via Ashton-under-Lyne and Huddersfield); and Sheffield to Lincoln.
A spokesperson for Northern said: "Most stations on penalty fare routes will have either ticket offices or ticket vending machines and so customers will have the opportunity to purchase tickets before they travel.
"In addition, tickets may be bought at any time before a customer boards a train by using the Northern App, with no booking fees incurred.
"If these facilities are not available at stations, or if offices are closed or machines out of order, customers will still be able to buy a ticket from the on-board conductor."
For customers wanting to pay cash, but ticket machines are card only, Northern says they will be able to obtain ‘promise to pay’ notices from the machines which can be presented, along with cash to the conductor – the full range of fares will still be available on board.
If customers board from stations with ticket machines or staffed ticket offices, but do not have a valid ticket, they will only be eligible for standard fares if buying from the conductor. If a customer chooses to do this, they may be issued with a penalty fare if an authorised collector is encountered.
"We are investing millions of pounds to introduce more than 600 new ticket machines across the network and have developed our website and mobile app to give customers more options and to make buying a ticket easier than ever before," the spokesperson added.
"However, there will still be some circumstances in which customers are unable to buy tickets and our authorised collectors are able to use their discretion to ensure no-one faces unfair penalties.
"Where customers do feel a penalty fare has been applied wrongly there is a tried and tested, independent appeals process which is used across the country."