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Locking PDF Files

I remember years ago there was a way to lock a PDF file and only allow it to be printed. This was great for e-signing a document and sending it on. Nobody down the line could alter the document or remove your sig without the password. This would be great with Preview but I cannot find how to do it. Is it possible anymore?


Comments: 3 Responses to “Locking PDF Files”

    4 years ago

    You can lock any file in the Finder by using File, Get Info and then checking Locked. Works for PDFs. But there is no way to really prevent someone from altering a document if you allow them to access it.
    For instance, they could open it and read it, and then save a copy of it and alter that copy. They can simply unlock it.
    Now if you have a pro-level tool, like Adobe Acrobat, then there are security features you can set in the PDF that will restrict opening, editing and printing. There are a lot of options. But it is mostly up to the reading software to enforce them. So it may help in a situation when a friendly recipient (a client, etc) gets a document and you want to encourage them not to edit it. But someone who really wanted to could break this and edit, print or recreate the document.

    Marcia Moore
    4 years ago

    If I receive a pdf file from someone who asks me to update missing info, how can I do the changes right on that PDF form?

    4 years ago

    Marcia: In that case I would imagine that the PDF would be sent to you unlocked. In addition, the person creating the PDF should make it in such a way that there a blank fields you can fill in. You can do that right in Preview by clicking on those fields and typing. That would be consistent with them asking you to “update missing info.”

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