Is it possible to use a credit card with a foreign billing address to buy items from a local Play store? I have a Visa credit card from a German bank with a billing address in Germany registered in my Google Wallet. I have successfully used my Wallet to pay for online purchases from several online service providers in different foreign currencies so I am sure the credit card is correctly registered in my Wallet account. However, while physically located in the UK, I cannot complete any purchase from the UK Play store. At the point when I need to select my preferred payment method from my Wallet account, it shows my registered credit card greyed out with the text "Unsupported Payment method" next to it.
From my own experiences, they do not allow this.
When I am in the US with my Australian google play account [and Australian credit card], I am unable to make any purchases from the play store. The reason being the US play store refuses my card details due to it's Australian address.
This may vary from region to region. But generally for the US and UK [not only Google Play], they enforce regional restrictions in a more strict manner due to licensing restrictions of the multimedia content, ie: music and movies.
As far as I know Google doesn't allow the use of International cards (at the moment).
I also heard from some other people (and t0mm13b acknowledges it too apparently) that the Play Store looks at your current SIM card to know your home country. So maybe if you could get your hands on a German SIM card (maybe an old one that doesn't really work anymore), you can still pay for applications.
Or you can have a look for some cheap credit card in the UK.