Update (27th Aug, 13:45 BST): Further digging suggests that the change could be thanks to PSD2, a new payment directive adopted by the European Parliament. PSD2 is said to add new levels of protection for those making purchases online and make cross-border European payment services safer, and it comes into full effect on 14th September.
Nintendo hasn't confirmed the reason behind dropping credit card support, but it would appear that it might simply be avoiding the need to update the 3DS and Wii U systems to conform with these new standards.
Original Article (26th Aug, 16:00 BST): Nintendo's European Twitter account has revealed the 3DS eShop and Wii U eShop (at least in Europe) will no longer allow users to top up their funds with a credit card, as of next month.
As of September 2019, credit cards cannot be used to add funds on systems in the Nintendo 3DS family or Wii U consoles.
At the time of writing, it's unknown if this will extend to other regions. We'll update this post when we get more information.
For now, here's the Twitter announcement, including a link with step-by-step instructions on how to add funds to your NNID using a credit card:
1. Ensure that the Nintendo Network ID (NNID) on your system is linked to a Nintendo Account.
- See here for more information on how to create a Nintendo Account.
- See here for instructions on how to link a Nintendo Network ID to a Nintendo Account.
2. Visit https://ec.nintendo.com/my/balance_add, select the payment method you would like to use and follow the on-screen prompts to complete the process.
3. Once you have added funds to your NNID this way, you can use them both on the Nintendo website and directly within Nintendo eShop on your system.