Some rail commuters in England will face a rise of nearly 6% for their season tickets next year.
Fares in England, Scotland and Wales will go up by 4.2% on average. Last month, the PM intervened to limit average rises to 1% above inflation.
The biggest rise in 2013 would be 5.9% - from £4,588 to £4,860 - for an annual ticket from Canterbury to London, according to watchdog Passenger Focus.
It said firms had showed constraint but commuters would still "feel this pain".
While Passenger Focus says the £272 increase in the Canterbury to London annual ticket will be the biggest, it also highlights ticket price rises including for the Bournemouth to London route - up £240 to £5,988.
Examples of new prices
- Canterbury-London: £4,860 (up 5.9%)
- Llanelli-Swansea: £624 (up 5.4%)
- Ludlow-Hereford: £1,992 (up 5.3%)
- Tonbridge-London: £3,796 (up 5.2%)
- Aylesbury-London: £3,632 (up 3.2%)
- Ellesmere Port-Chester: £720 (up 2.3%)
- Shenfield-London: £2,704 (down 0.6%)
Source: Passenger Focus
And an annual ticket from Gloucester to Birmingham will cost an extra £140, it says.
In August, it had been announced that rail fares in England would rise by an average of 6.2%.
The Retail Prices Index (RPI) measure of inflation as of July 2012 - which stood at 3.2% - plus 3% was initially used to calculate the average rise.
But last month, David Cameron announced the average rise for the next two years would be capped at RPI plus 1%.
The figure for 2012 is therefore RPI as of July 2012 - 3.2% - plus 1%.
Train firms are able to raise some season tickets above 4.2% as long as the average increase is no more than that ceiling.
Some tickets will rise by as little as 2.3% while one ticket, from Shenfield, in Essex, to London will be £16 cheaper, at £2,704.
'Welcome promise' Rail Minister Norman Baker said the government had taken "pro-active steps" because family budgets were being squeezed.
"Successive governments have instructed train companies every year to increase these regulated fares on average by more than inflation”
Association of Train Operating Companies
"This decision puts an average of £45 per year back into the pockets of over a quarter of a million annual season ticket holders," he said.
But Passenger Focus chief executive Anthony Smith said that, "after years of above-inflation fare rises, fresh increases are piling pressure on already high fares".
"The government and the rail industry must now work together to deliver on the welcome promise to get fare rises in line with inflation."
The Association of Train Operating Companies, meanwhile, said it was the government "not train companies that decides how much season tickets should rise on average each year".
"Successive governments have instructed train companies every year to increase these regulated fares on average by more than inflation." a spokesman said.
'Government collusion' BBC transport correspondent Richard Westcott said 2013 would be the tenth consecutive year that regulated rail fares had gone up by more than inflation in England.
Regulated fares, which include season tickets and off-peak intercity journeys, make up half of all fares.
Consecutive rises had left the country with some of the most expensive trains in Europe, our correspondent said.
Manuel Cortes, leader of the TSSA rail union, said thousands of commuters across south-east England would be "paying more than £5,000 a year for their season tickets because of the government's unfair annual inflation-plus fare rises".
And RMT general secretary Bob Crow said train companies "with the collusion of the government, will be jacking up fares by up to 6% in the new year as they launch a full-frontal assault on passengers in the name of profit".
There are no fare increases currently planned in Northern Ireland after a 3% rise in April.
