You can't get in
Which way back applies depends on what you have lost. Most of them have to be set up before you need them, so it is worth reading this on a good day.
Set a recovery address now, and save your recovery codes. They are on the Profile page. Between them they cover almost everything below, and neither can be set up after the fact.
You've lost the inbox you sign in with
A recovery address is a second inbox that can point your account at a new sign-in address. Ask for a recovery link from the sign-in page and follow it from that second inbox.
What it deliberately cannot do is sign you in, read anything, or send anything as the organization. A magic link is the whole credential here, so a second address that could receive one would be a second key of equal strength — usually to an older, less protected mailbox. It authorises exactly one thing: setting a new address, which you then sign in with normally.
Owners are required to have one, and are asked to set it before they can do anything else. The owner is the one person nobody can remove, so an owner with no way back is an organization nobody can repair.
You've lost the phone with your authenticator
- Your recovery codes. Ten, single-use, shown once at setup. Any of them gets you past the challenge, and then you can enroll a new phone.
- Ask the owner to waive it for you. Seven days, visible on the admins page, revocable. It waives that organization’s requirement; it does not touch your authenticator, which belongs to you rather than to any organization.
More on both under two-factor authentication.
You're the owner, and you've lost both
This is the case with no self-serve answer, and it is worth being plain rather than reassuring. A recovery address cannot clear a second factor and never will: one inbox that could both move an account and clear its authenticator would be a complete takeover of everything, and that inbox is typically the older and less protected of the two.
Write to us. Recovering from this needs an operator, and it is the only situation here that does.
The owner has left and nobody can change anything
You do not need the owner. Any admin can ask to become owner, and the approval goes to the organization’s own verified address rather than to any person — see handing the organization over.
Nobody can read the organization's address either
Then the chain has run out: the address is the anchor everything else hangs from, and there is nothing left that proves the organization is yours. This one also needs an operator, and it is adjudicated on control of the domain, which is the only ground truth available.
It is the strongest argument for the shared-mailbox advice: an address several people can read is one that outlives all of them.
The sign-in page never says whether an address exists
Ask for a link with an address that has no account and you get the same “check your email” page as everybody else, and no email. That is not a bug and not unhelpfulness: anything else would let anyone type addresses and learn which organizations exist here.