What you can undo or recover

There is no general undo. What there is instead is a set of actions that are reversible by design and a smaller set that are not, and the difference is worth knowing before you click rather than after.

The rule of thumb: archiving, closing and marking things can be undone. Deleting cannot.

Reversible

Archiving a request. Archive (the eye icon on the request) takes it off the portal and your default list without touching the request or anything already submitted against it. Tick Show archived and click Restore to put it back, answers and all. This is the right tool for a request you no longer need, because it keeps the record of what people gave you.
Approving or rejecting an upload. Click Approved to remove an approval (if document retention has already deleted the file, that does not bring it back). Click Rejected, then Clear rejection, to put the file back to Needs review; the reason you wrote is lost, and a rejection email that has already gone stays sent.
Closing a portal. Reopen portal turns the same links back on, so nobody needs a new one. See the life of a portal.
Replacing a library file. The old file moves to Versions on its row, and Restore brings it back everywhere the file is attached. See your files library.
Editing terms. Every save keeps the previous version, and restoring an old one copies it forward as a new version. See terms and conditions.
Hiding a sidebar row. A display choice for your login only. Customise menu, then Show all, brings them back.
Queuing a batch of invites. Cancel batch stops it, but only while it is still waiting. See batched invite emails.
Closing your account. The deletion runs 48 hours after you confirm. Inside that window, sign in and click Restore my account; signing in alone cancels nothing. See deleting your account.

Not reversible

Deleting a portal. This destroys every document uploaded to it, with the expiry dates and approval history. The confirmation counts the files first and points you at closing instead.
Deleting a request. The answers and uploads attached to it go with it. Once anything has been submitted, you have to archive the request before you can delete it, which is your second chance.
Deleting a contact. Their record goes, and so does every file and answer they submitted, across all your portals.
Deleting an upload or an answer. A deleted file is gone. A cleared answer, or a terms acceptance you or the person clears, is kept in the request's history as a record but does not come back as the live answer. See tracking changes to a request.
Archiving a terms document. It leaves the list you pick from and there is no unarchive. Acceptances already signed against it are untouched.
Revoking a link. The URL is dead for good. Generating a new one issues a different URL, so the person needs the new one. See resending and revoking a link.
An email that has gone. Once a message has left, it has left.

Recovering the thing itself

There is no per-record restore, and support cannot undelete one item for you. What you can do, before any big tidy-up, is take your own copy: exporting your data downloads everything on the account as files you keep. Take one before deleting portals in bulk and you have the record even if you delete the wrong one.

Documents people uploaded are not in that download. The export article covers how to request them.

The two mistakes worth designing against

Deleting a finished intake instead of closing it. Closing keeps the paperwork and can be undone. Deleting is how a year of insurance certificates disappears in one click. If in doubt, close.

Revoking a link to fix a missing email. It makes things worse: if the original email is sitting in their inbox after all, you have killed the link inside it. Resend first.

Getting help

If you have deleted something you needed, open a help ticket straight away and say exactly what went and when. We will tell you honestly whether anything can be done.