Hello AnibalOsegueda
Please help us with this issue
We are a customer support page where volunteering customers help other customers. We are not the SBB customer service; for this, you could contact SBB by phone anytime: +41 51 225 78 56 (24/7, waiting times may apply).
→ To possibly solve the issue: Please try entering all passenger data as well as all credit card data in full capital letters and retry.
It is hard to find out why for some people the credit card purchases are difficult. Every single day there are hundreds of thousands of credit card payments made through SBB. It might be your IT equipment, or the location from where you try purchasing, or what ever.
→ There is actually no need to purchase tickets in advance unless you want to purchase a saver offer.
All regular ticket offers are costing the same no matter the time of purchase being six months or two minutes before departure. And, since train tickets do not come with a seat allocation, there is even no need to purchase tickets in advance for the sake of securing a free seat.
https://community.sbb.ch/blog/23887-demystifying-seat-reservations-on-swiss-trains-a-comprehensive-guide
Kind regards,
Roland