The feature has been in the works since Fortnite cross-platform play on the PlayStation 4 was first introduced. Then you'll choose a Secondary Account to merge and disable. You can then use this primary account on any platform, since every version of Fortnite now allows for cross-platform play.
To be eligible, one account must have played on Xbox One or Switch and the other on PS4 to be eligible for merge. If you used a third-party login (liked Facebook) on both of your accounts, it will be automatically unlinked from the secondary account. And whatever progress or money you made on one account couldn't transfer over to the other.
It's a pretty inelegant solution to an awkward problem, but at least some sort of progress has been made. In addition to this, players must have used each account before September 28th.
Merged accounts also can't be now banned, or disabled and players will need to be able to access all email addresses associated with the accounts they want to merge.More news: Anthem endgame video shows contracts, Strongholds, Cataclysms, more
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Your account must not now be banned or disabled.
In-game items and Vbucks will be held for two weeks before they're merged to your primary account. Don't panic! You'll have to wait two weeks for the V-Bucks and cosmetic items you had on your secondary account to appear on your primary account.
To merge your accounts, simply go to Epic's Account Merge page and follow the instructions. The biggest stuff you'll have to leave behind on your secondary account are any Creative Mode Islands you've built and any Save The World mission/level progress (individual items like Llamas and Heroes will transfer).
There are a few conditions imposed on account mergers, but they all make sense. This means that all the cosmetic items and V-Bucks that you've earned across platforms will be conveniently gathered in one place.
The first stage of the process is heading over to the Epic Games website and selecting the merge account option.