Next month I'm travelling from London to Dordrecht using Eurostar to Rotterdam. I booked my tickets via the NS International website and have been issued with Eurostar e-tickets for the London to Rotterdam leg of the journey, which I can simply save in the "wallet" on my phone, and NS e-tickets for the Rotterdam to Dordrecht leg. I've saved these as PDFs on my phone and can also access them via the NS International app, but they say this ticket is only valid if it is of good quality, clearly legible and printed (colour or black & white) without any changes on blank, white A4 paper.
Will they still be valid (and will the barcode on them still work the ticket gates) if I present them on my phone, or does NS insist that e-tickets for international journeys must be printed out?
Will they still be valid (and will the barcode on them still work the ticket gates) if I present them on my phone, or does NS insist that e-tickets for international journeys must be printed out?