I bought a $10 PSN card online. A physical card was shipped to me. I scratched the silver to reveal and redeem the code, but got the error message, ""The prepaid card could not be redeemed. Please try again later."
I contacted Sony Playstation customer support and they stated, "the issue with the voucher code, it has not been activated by the retailer." and " The code you purchased requires activation by the retailer. This is done by the retailer upon purchase and only the retailer can activate a card."