My editor uses Word and I write in Scrivener

Sending the book out

Open File › Compile, set Compile for to Microsoft Word (.docx), pick a manuscript format, and compile. Before you send the result, make a dated copy of the project with File › Back Up › Back Up To…, and put the same date in the Word file's name. You will want to know exactly which text the editor saw.

Ask the editor to work with Track Changes on and to put questions in comments. Many professional editors work that way already. It matters to you because what comes back is then a list of proposals rather than a silently rewritten copy.

Bringing the changes back

There are two honest routes. Neither is automatic.

Settle everything in Word, then import. Work through the file with Review › Accept and Reject, answer or delete the comments, and save a clean copy. Bring it into Scrivener with File › Import; Scrivener 3's Import and Split can cut it back into chapters at a separator you choose. This is quick for a heavy line edit. The cost is that imported documents arrive new and bare of the synopsis, label, and snapshots each original carried. Moving them into place and retiring the old ones is handwork. Settle every tracked change before importing, because how an unresolved revision comes across depends on the version.

Apply the changes by hand. Keep Word open beside Scrivener and walk the edits in order, typing each one you accept into the matching document. Snapshot each document first, and turn on Revision Mode from the Format menu so your new typing shows in color. It is slow over a whole book. It is also the only route that leaves your binder, metadata, and history exactly as they were, and some writers find that deciding every change with their own hands is half the value of the edit.

One thing to set expectations: Scrivener is built for one writer at a time. Its manual allows several people to work from a shared project only with care. Its firm rule is never to open a project for editing while someone else is editing it, so an editor cannot mark up the book alongside you.

In Tabularia

A Scrivener project imports directly: choose Import folder as new manuscript and select the .scriv package and its binder becomes manuscript structure, worth reading against the original once. From there the round trip through Word is optional. Invite the editor as an Editor; they sign up for a free account, mark up the draft in their browser, and submit. Their review arrives as a draft of its own, and you accept or reject each change where it sits in the book, with nothing to retype and nothing re-imported.

Where it does not help: an editor who will only work in Word. Tabularia can export a DOCX for them, but it has no command that compares a returned Word file against your manuscript. An imported DOCX becomes a separate project, with tracked insertions taken as accepted and text marked for deletion left out, so for that editor the hand method above is still the careful one.