Rail firms have been "misleading" customers by selling tickets for services over Christmas despite knowing they will not run, a watchdog says.
Other customers were not told their trips would be disrupted by engineering works, Transport Focus added.
Six rail companies also failed to release advanced purchase tickets for the festive period 12 weeks ahead.
Industry body the Rail Delivery Group said its members would "develop a plan" to address the complaints.
Transport Focus found more than 2,600 incorrect journeys – those already cancelled or scheduled to face disruption – on offer during the Christmas week alone.
The group also found that by 13 October – 11 weeks before Christmas – reservations had not opened on Great Western, London Midland, South Western Railway and Southern – despite regulations stating they should.
Only 15% of services were open for reservation on Greater Anglia and 25% on Virgin Trains.
Transport Focus chief executive Anthony Smith said: "Failure to release timetables 12 weeks ahead of travel can mean passengers buy tickets for trains that will not run.
"That can't be right. Train operators' advice is to book early at Christmas to get the best deal.
"But if the timetable has not been finalised only more expensive 'on the day' tickets can be bought."
Helen Firth, 37, from Surrey commutes to London for work and says getting home on time is very important to her as she has a nine-year-old son.
But she can't plan travel around Christmas because she does not know what the trains will be like.
"It's unfair if someone's forked out a bunch of money, but don't know if their train will be delayed," she says.
"Companies should at least advise people so they have the option of knowing and planning other routes."
In response to the Transport Focus complaints, Paul Plummer, chief executive of Rail Delivery Group, said: "We clearly all agree this is important."
He said he would reply "more fully before Christmas".
Transport Focus are calling for a network-wide review to ensure train operators publish correct timetables 12 weeks in advance.
They have also asked for incorrect information to be removed from online timetables and say passengers who have already bought tickets must be notified when there are changes to their journeys.