Sony has temporarily suspended the PlayStation promo codes feature following a surge in traffic on the gaming service, due to the PS4 launch in Europe, Australia and Latin America.
So, for the moment, money cards and game vouchers won’t work. Here’s Sony official announcement about the matter:
We are aware that users are experiencing some disruption to the PSN service. To minimize the inconvenience we have suspended the “redeem voucher” functionality while we investigate further. Unfortunately this means that money cards, product vouchers, PlayStation Plus vouchers, PS3-PS4 upgrade vouchers and any other vouchers for digital content are not redeemable at this time. Other PSN features such as log in, online multiplayer gaming, PlayStation Plus trials, PlayStation Store (excluding voucher redemption), Trophies, messages, friends, etc are all available.
We apologize for the inconvenience and will provide an update soon.
PSN users in North America are also affected: