Why cant i use my Microsoft account balance to purchase xbox 360 games?

Hi there

This is due to the Microsoft balance (Microsoft store and Xbox one) and Xbox balance (which was used for 360 store) are 2 different systems in place that is why you cannot use Microsoft account balance to purchase the game. But if you had a gift card and
redeemed it on the Xbox 360 console you would be allowed to use it on the 360 store.

You can use your Microsoft account balance if you make the purchase from a 360. The One store has never been updated to work with Microsoft account balance for 360 or original Xbox game purchases.

If they could find a way to make it work, I'd love that. I get why, but it'd make thing a lot nicer if what you want were possible

In order not to break Xbox 360 games, they are all bridged to the 360 store. There are security issues doing this. If you eish to use your bakance yo purchase you must use an actual xbox 360

The One store has never been updated to see the Microsoft account balance as a valid payment option for backwards compatible content. You would have to make the purchase on a 360 console in order to use the funds.