Fewer strike days and more people switching to digital tickets has fuelled an uptick in sales for Trainline this year, the travel platform said.
The company said competition between rail firms was heating up across Europe.
Trainline generated £2 billion in net ticket sales from UK consumers over the six months to August, 15% higher than the prior year.
UK revenues – the amount of income that Trainline generates from ticket sales and other services like advertising – jumped 17% to £106 million year-on-year.
Trainline gathers coach and rail journeys from hundreds of operators around the world, with most people booking through its app.
The business makes money from earning commission and booking fees on ticket sales, as well as cash from advertising and services like travel insurance.
Trainline said e-ticketing now represents just over half of all ticket sales, tipping the scale from paper tickets previously being the majority.
It also benefited from there being fewer strikes organised between March and August – six, compared with 11 last year – which halted some train lines in the long-running dispute over jobs and pay.
The impact on UK sales was about £3 million to £4 million per strike day this year, compared with £5 million to £6 million last year.
Total ticket sales jumped 14% to £3 billion over the first half.
This was driven by Spain and Italy where there is strong competition among rival operators, but dragged down by France and Germany, including the impact of travel disruption during the Paris Olympics.
The platform said it was focusing more on generating revenues from means other than commission on ticket sales.
This helped offset the impact of faster growth in commuter and on-the-day travel, which it said typically earns them less money than longer-distance travel.
Trainline said that its improved first-half performance means it is now expecting ticket sales and revenue growth at the “top end” of its forecasts, with adjusted earnings predicted to beat its previous guidance.
Chief executive Jody Ford said: “Competition between rail carriers is growing across Europe and as the aggregator of choice we deliver the value and convenience customers want.
“This is most clearly demonstrated in Spain, where we have tripled net ticket sales in the last two years, with over one million customers transacting in the last 12 months alone.”