An upcoming system update for Nintendo 3DS will let users combine their 3DS and Wii U eShop balances into a single Nintendo Network ID.
The update means that eShop funds will no longer be split between Nintendo 3DS and Nintendo Wii U, but unified in a single account.
The update was announced by Nintendo of Europe president Satoru Shibata during today's Nintendo Direct update, who added that the firm would "continue to improve our offerings with Nintendo Network IDs".
"Eventually more of our services will use them," he said, including Miiverse on Nintendo 3DS.
The system update is expected to launch next month.
Source: Nintendo Direct November 13, 2013