Region when buying something is always on the US

Well the thing is where did you buy the code? Us or uk?

When buying stuff it is best to buy from your local region

With region locked content you must be physically in the country of your account

Suggestion when you create an account always use the correct country

that's is because currency has always been region locked even during the ms points dayd

The region migration tool does mention that currency doesn't transfer

When buying currency it's best to buy from your actual region and use the correct account region

@Diemetreo

regardless of previous experience

your account region and actual region should always match as per the terms of use

as long as your account region doesn't match your actual region you will run into proble,s with downloading content

also it is best when buying things to actual buy from your actual region rather then another continent

Since you have an Italian account and since ms points are region locked you would have to buy ms points from Italy. The Gold subscription howver is not region locked so you can buy it from Australia. As for Italian apps being
usable when you are out of region you may experience issues using any of the Marketplace features when you are out of region. That is why it is always recommended to create another region specific account when you leave your originating region.

When purchasing Live time and ms points it is always recommended that you buy it from the same region as your XBL account. In your case that would be the Philippines.
If you try to use any other regions ms points on your account it will not work and you will always get an error code.