A document you send a client represents your work — which means the file itself should look as finished as the content inside it. Two things undermine that more often than people expect: hidden metadata left over from drafting, and a final file that anyone who gets a copy of it can open and edit.
Documents built from a shared template or edited over several sessions often carry old author names, a previous client’s name in the title, or leftover comments from an internal review — none of it visible on the page, all of it visible if the client opens the file’s properties. Run a check with PDF metadata before sending anything, and see How to Remove Hidden Data from Word, Excel, and PowerPoint if the source file hasn’t been converted to PDF yet, since tracked changes and speaker notes hide in the original format, not just the export.
A contract or invoice a client can silently edit and forward isn’t really final, so lock the version you actually send. Lock PDF adds a password so only someone you’ve given it to can open the file — send the password through a separate channel (a text message, a phone call) rather than in the same email as the attachment, so intercepting one doesn’t hand over both. The reasoning behind that split is covered in How to Email Sensitive Documents Safely.
Drafts and finals deserve different treatment. If a document is going out for review before it’s final, mark it as such — a “Draft” watermark stamped across every page makes it obvious at a glance that comments are still open and the content isn’t locked in yet, and How to Add a Watermark to a PDF Without Adobe covers getting the opacity right so the label reads without fighting the text underneath. Once it’s approved, send a clean final copy without the watermark, locked with a password. When the returning copy is the approved one, an Approved stamp in a corner does the opposite job to a watermark — a single mark, out of the way of the content, rather than something repeated across the page. The same tool places a signature image or a company seal, which is what a client is usually looking for on a countersigned contract.
Before you hit send: confirm the file opens correctly with the password you’re about to send, on a device other than the one you created it on; double-check the recipient, since a locked file sent to the wrong person is still a mistake, just a slightly better-contained one; and keep an unlocked copy for your own records, since only the client’s copy needs the password.
Lock PDF or check PDF Metadata before you send — both free, no account required, nothing saved on our end.