I Forgot Which Email I Used

A few places to check before you assume it's lost.

Check these first

• Search your email inbox for "XKD" — even without a welcome email, you may have used it elsewhere (a password manager, a note app)
• Check any password manager or browser-saved-password list for "users.xkd.org" or "XKD.org"
• Think about which of your regular email addresses you'd most likely have used when you registered

If you have a saved recovery code

A recovery code is tied to your account regardless of which email you remember — if you saved one when setting up Account Security, you may still be able to use the recovery flow if you can supply the right email once you find it.

If you truly can't determine it

Contact help@xkd.org with as much identifying detail as you can — your XKD number if you remember it, your pet's name, or your name and approximate registration date. An admin can help locate the account.