It didn't succeed in saving the data. Does it maybe indicate any missing data? Are any of the fields marked in red or something similar?

If it wants to have your phone number: just use 0 and 9 random digits, such as 0307515155. NS insists on a Dutch phone number. They will never call you though.

The only bit marked red was when I put the postcode in it didn't recognise the address and told me to type it in manually. I left “toev” blank (I think that’s just an apartment number or something which doesn't apply to me). It maybe just doesn't like my address for some reason?

Dutch postal codes are all in the format 4 digits + 2 letters. The digits are for the postmen and bear no relation to other numberings-the letters fine tune the way the mail is stacked in the bags.

This is a lot different from UK-way.

NS in general really distrusts and makes it as hard as possible for those foreigners to register-most likely the next hurdle will be that it will not accept your bank account.

As I always use my own chipcard I am not famliair with the ways these accounts work. But it should be possible to just buy, with even a creditcard, but then every time you are just a new customer and have to give all details again.

I’d heard that sometimes the machines at the stations don’t like UK credit/debit cards either so I thought this way might make things easier. I can get slightly more expensive tickets on thetrainline.com so I might just do that instead. Thanks both for your help.

You don’t need an account to buy a ticket.

Thank you Tochjo, you’re right! Just tried the app without being logged in and sure enough it let me buy a ticket with just an email address!

Right, so the postcode bit of the form is buggy.

I have my Belgian postcode in there but I can't change it. It may be the case that the current form insists on a postcode in Dutch format despite the selection of another country. That's bad programming.

You don’t need an account to buy a ticket, but how do you view them in the mobile app if the app wont let you save your personal address data?...It would be better than bringing paper copy of tickets