On Xbox one it is unfortunately the case that if you want to buy an Xbox 360 game you can only pay by credit card. Since I don't have a credit card that is accepted by Microsoft, I wonder if I can simply buy a digital code from the game I want to have and redeem it on Xbox one. Anyone who has done this before and knows whether you still need a credit card?
You can also buy via PayPal, I don't know where you got all this half information from, but Okeh, whatever. With my One I bought all 360 games that I now own via PayPal. Never had problems. - And yes, you can redeem 360 voucher codes on One. You can even do this on the Xbox app for smartphones. You can even redeem games that are not backwards compatible on One. You have to download such games on the 360. So: just enter the code. It is also not redeemed immediately, when you have finished writing now press enter, there's then an overview window that shows what the code is for and therefore requires confirmation (just simply tap / click Accept) and then the game / DLC is yours.
Thanks for the answer