Error Code: 9001-1663
When attempting to redeem a Nintendo eShop prepaid code on the Nintendo website, error code 9001-1663 is displayed.
Nintendo eShop prepaid codes can only be redeemed on the Nintendo website at the time of purchase if you do not have sufficient funds in your account to purchase the desired product.
What to Do:
On the Nintendo website, select a game or software and proceed to purchase it. On the checkout screen, you can choose to use a Nintendo eShop prepaid code. Otherwise, you can redeem your prepaid code directly on Nintendo eShop for Wii U, Nintendo 3DS or Nintendo Switch.