Trainline is valuable for one simple reason: it reduces the friction of comparing and booking rail travel across multiple operators from one interface. For travellers moving around the UK and Europe, having schedules, tickets and journey information in one app can be considerably more convenient than checking operators separately.
Its current referral offer is straightforward: an eligible referred customer can receive 10% off a first booking in the app, and the referrer can then receive a 10% discount as well. As with any promotion, eligibility and current terms should be checked before booking.
Independent feedback is positive overall at substantial scale, particularly for ease of booking and access to journey information. The limitations are equally worth knowing: booking or administrative fees can apply, some journeys may be cheaper when bought directly from an operator, and refunds or complex itinerary changes can introduce extra friction.
Trainline is therefore strongest as a convenience and comparison tool, not a guarantee of the lowest possible fare. Used with that distinction in mind, it remains a very practical travel app.
— The Rebel Marketer