Drupal Commerce: Can I split payment over multiple credit cards?
No

It is not possible now. It was requested, and it is Closed (won't fix) - if you want it, you need to code it yourself.


  This isn't something Commerce can do out of the box, and I'm not entirely sure it would fit in. However, in a contributed module, you should be able to look at the order balance before moving forward to the checkout completion page and requesting additional payment from the customer if necessary. For now, I'm just going to have to mark this "won't fix" as no easy ideas come to mind for how we could make this abstract enough to solve in core. The main problem in core would be how you visualize the outstanding balance and accommodate both on-site and off-site payment methods.