Can't buy apps via iPhone, but no issue on iPad

Hello everyone,

I'm having some trouble buying a (non-free) app from the App Store on my iPhone5 with iOS 6.1.2 for some reason. I also have iOS 6.1.2 on my iPad 2, but I have no issue whatsoever when I'm trying to buy an app on the iPad. Buying an app directly from iTunes on my iMac also works flawlessly. But for some reason whenever I try to buy an app from my iPhone, I get the following notification:

It first tells me to give my password (which has always been the case for me). Then it tells me that I have to enter payment details… I've already connected my iTunes/App Store account with Click2Buy a long time ago, but for some reason I can't select Click2Buy in my iPhone so it's currently impossible to buy anything from it.

It's a little vague I know 🙂 I can't really think of any other bit of information I can give to make this any clearer to be honest, but if anyone has seen this happen before, please help! 🙂

Sincerely,

Joram