I am a hard stack developer that works with finance websites and as I did for Fit My Money service, I didn’t save credit cards info because it can be very dangerous for you and for your customers. By creating database with that info can really influence you as a professional because if you will lose information from this source you will get a lot of angry people who will look for you. For example, a thousand of information from Facebook were leaked by the easiest way and people right now are really worrying, because you can easily find someone who is selling it to the other hackers. Try to find another way to do it, use 3rd party services, or just forget about this idea!