Payment Method Registration Errors [Error Code 401 and 601]

[Lament]

Good to know, Lament. I have the same information as you (Country: Brazil, Region: The Americas). The difference is that I don't have any subscription saved as you already had several weeks ago, and now when I try to register a credit card (which is different from paying), it returns me Error 601. I guess I'll just keep trying this week and see if I get interested in other game with a competent billing system.

Are you registering through MogStation or the account management page? If the former, try the latter - that's how I registered mine. In the Lodestone: Help&Support > Square Enix Account Information > Square Enix Account Management System > Register/Update Payment Method. If you succeed, then go to MogStation and try setting up your sub.

If that doesn't work either, I have no idea. ): Good luck.