Fortnite was announced for Nintendo Switch earlier today and released just minutes after its announcement. While it was assumed that Nintendo would participate in the crossplay aspect of the game, it has been confirmed by Epic’s Nick Chester all the same.
Xbox One, PC, Mac, and mobile.
— Snake Chester (@nickchester) June 12, 2018
That’s pretty much every platform Fortnite is on except the PlayStation 4. Sony has been traditionally very reluctant to support crossplay with other consoles, though it does support crossplay with PC and mobile. Unfortunately, as has been discovered today, logging in with an Epic account tied to a PSN ID on other systems is not allowed. This had previously been the case on the Xbox One, but it was not clear if it was simply a one-off issue. So if you want to take progress from Fortnite PS4 to Fortnite Switch, you’re out of luck and will need a new account.
Source: Game Informer Fortnite Switch Can Play Online With Xbox One, PC, Mac, And Mobile