NS is not going to call you, just enter a random phone number that matches the Dutch format, e.g.: 030-7515155.

Good afternoon Kolmogorov and welcome to the NS Community!

Unfortunately no, it's not possible to order an NS Flex product without a valid Dutch phone number. Sadly, the ordering system doesn't yet accept other inputs.

You can follow the suggestion from Henk_NL, however. The phone number from our Customer Service is indeed often suggested as a workaround (030-7515155). I do want to recommend to contact our Customer Service once you've finalized the order, to have the phone number changed to either your actual personal number, or to have it removed.

And then get the same problem when you want to change your Flex subscription and have to do that all over again. Entering a phone number like 010-0000000 or 06-12345678 also works.