How to watermark a PDF, and what to write on it

To watermark a PDF for free, use software you probably already have. In Word, choose Design, Watermark, then save as a PDF. In LibreOffice, use Format, Watermark, or tick Sign with watermark when you export. On a Mac, add a text box in Preview and fix it with File, Print, Save as PDF. If you have Acrobat, it’s Edit, Watermark, Add. Free online watermark sites work too, but check what they do with your file before you upload a payslip or an ID.

This guide explains how to watermark a PDF with each of those four programs, following the official help from Microsoft, LibreOffice, Apple and Adobe, checked on 24 October 2026. It also covers what to write for a rental application, a bank or an employer, where to put the watermark so it can’t simply be cropped off, and why a watermark never replaces redacting details such as a TFN, a Medicare number or a driver licence number.

How to watermark a PDF, step by step

The same five steps work whichever program you use. The program only changes the menus in step 2, and those are set out section by section further down.

1. Decide what it will say

Who the copy is for, what it’s for and when, for example “Copy for Smith Street rental application only · October 2026”. None of your own details go in the watermark: no licence number, no phone number, no date of birth. If the PDF is a scan of an ID document, cover what the recipient doesn’t need first, the way our guide to covering the details on a passport copy does for a passport.

2. Pick the program

If the document is still in Word or LibreOffice, add the watermark there and export to PDF. If it’s already a PDF, use Preview on a Mac, or Acrobat if you have it.

Program	Cost	Best when
Word	Part of Microsoft 365	The document started in Word
LibreOffice	Free	You want a free watermark on many pages
Preview	Built into macOS	The file is already a short PDF
Acrobat	Paid plan	You need batches or exact placement

3. Place it across the content

Large, partly transparent, and running across the middle of each page, not tucked into a corner where it can be cropped out in a second.

4. Save a new PDF

Save or export the watermarked copy under a new name and keep the original, unmarked, somewhere separate. In Preview, fix the text with File, Print, Save as PDF so it can’t be edited.

5. Check it before you send it

Open the PDF you’re about to send and confirm the watermark is on every page, that the recipient can still read what they need, and that the text is for this recipient, not the last one.

What a watermark on a PDF is for

Adobe describes a watermark as fixed text or an image added to a PDF to show ownership, carry branding or mark content as confidential. In an office or at home, that comes down to three jobs.

The first is marking a document’s status. DRAFT on a contract still being negotiated, so nobody signs the wrong version; CONFIDENTIAL on an internal report. Word ships with those ready to pick.

The second is recording who a copy was for. A payslip, a bank statement or a lease you send to an agent, a lender or a new employer will sit in an inbox or a shared folder for years. A line that reads “Copy for Smith Street rental application only, October 2026” puts the purpose on the page itself. If that copy ever turns up in a loan application you never made, the text shows it wasn’t meant for that.

The third is telling copies apart. When one document goes to several people, say a proposal to three prospective clients, a different watermark on each copy tells you which one travelled. If that proposal began life as a Word file, redact the details in Word before you export it.

What a watermark doesn’t do is stop anyone reading, copying or using what’s on the page. Names, numbers and addresses stay legible underneath, and, as the Acrobat section shows, the watermark itself can be removed with the right tool. It’s a label, not a lock.

What to write on the watermark

Decide the text before you open any program. It changes how useful the watermark is more than anything else, and it’s the part most people skip.

A good watermark answers three questions: who the copy is for, what it’s for and when. Some lines that work:

Rental

Copy for Smith Street rental application only · October 2026

Bank

Copy for home loan application, income check only · October 2026

Employer

Copy for HR, new starter onboarding only · October 2026

Police check

Copy for national police check application only · October 2026

For a rental, name the street rather than the agency. One agency can hold several of your applications in a busy month of inspections, and the address is what ties each copy to one property. For a national police check, the Australian Federal Police asks for scans of identity documents worth at least 100 points, so a dated line on each scan keeps those copies tied to that one application.

Keep your own details out of the watermark

A common mistake runs the other way: putting personal details into the watermark itself. Some people add their licence number or phone number “so everyone knows it’s mine”. That adds identifiers to the copy instead of taking them away, and repeats them on every page. None of the personal identifiers to remove before AI or before an email belongs in a watermark either.

The watermark should talk about the recipient and the reason, never about you. And if the copy belongs to a client, don’t put the client’s name in it; use the matter or the transaction.

Keep it short, too. If the text won’t fit on one readable line, cut it back to the recipient, one word for the purpose and the month. A long line forces a small font, and a small watermark is easy to ignore or trim.

Why COPY on its own is not enough

COPY or CONFIDENTIAL is better than nothing, but it fits any use at all. If the file resurfaces somewhere it shouldn’t, a single word says nothing about where it came from. A specific line does the opposite: “rental application only” on a copy that lands with a finance broker shows at a glance that it wasn’t meant for them.

That lines up with the rule the OAIC sets out for real estate agents covered by the Privacy Act: they can only collect personal information that is reasonably necessary for their functions or activities. The watermark has no legal force of its own, but it writes the purpose onto the document, where everyone who receives it can see it.

Where to place it: across the content

Placement matters as much as wording. A small mark in a corner can be cropped in a second, and the copy is as good as unmarked. A large diagonal watermark across the middle of the page, running over the important content, means retouching the whole page to get rid of it, and the retouching usually shows.

• Diagonal and centred. Most programs default to it, and it’s the hardest position to crop.
• Partly transparent. The recipient still has to read what’s underneath. If it hides a figure they need, the document stops being useful. A light grey at low opacity usually works.
• On every page. A watermark on page one only leaves the rest clean. Word puts it in the header, which repeats on every page; LibreOffice applies it to the current page style; Acrobat lets you set a page range.
• Repeated, for a stranger. For someone you trust, one watermark per page is enough. For an app or an agent you’ve never dealt with, repeat it in more than one place.

A watermark sits on top of the page and leaves everything else in the file as it was. If the PDF comes from a Word draft, remove tracked changes in Word permanently before you export, or the markup can travel with the watermarked copy.

How to watermark a PDF in Word

If the document started in Word, the simplest route is to add the watermark in Word and then save it as a PDF. Microsoft documents both desktop versions.

Word for Windows

1. On the Design tab, select Watermark. Presets such as DRAFT, CONFIDENTIAL and DO NOT COPY appear.
2. For your own wording, select Custom Watermark.
3. Choose Text watermark and type your text in the Text box.
4. Select OK.

Word for Mac

1. On the Design tab, select Watermark.
2. In the Insert Watermark dialogue, select Text and type your own text, or pick one from the list.
3. Adjust the font, layout, size, colours and orientation.
4. Select OK. If you can’t see the watermark, Microsoft says to go to View, Print Layout.

Word for the web, and the header catch

Microsoft says Word for the web shows watermarks already in a document but can’t change them or insert new ones. Use Open in Word to do it in the desktop app.

Word keeps the watermark in the header: Microsoft’s own instructions for moving it start with opening the header. That has a practical side effect. If you later run Inspect Document to clean the file, its Headers, Footers, and Watermarks category can strip the watermark out. To clean the properties and keep the watermark, don’t choose Remove All on that row. Our guide to removing metadata from Word and PDF walks through the rest of the inspection.

With the watermark in place, go to File, Save As and choose PDF as the file type. Keep the unmarked Word file too, for the next recipient.

How to add a watermark to a PDF free with LibreOffice

LibreOffice is free, runs on Windows, Mac and Linux, and gives you two ways to add a watermark.

In the document: Format, Watermark

In Writer, LibreOffice’s help points to Format, Watermark (Layout, Watermark in the tabbed interface). The dialogue has five settings:

• Text: what the watermark says.
• Font: picked from a list.
• Angle: the rotation, applied anticlockwise.
• Transparency: 0% is fully opaque and 100% is invisible.
• Colour: chosen from a palette.

The help adds two notes. You can’t choose the font size or style, because the text is scaled to fit one line. And the settings apply to the current page style, so if your document uses more than one, check that every page carries the watermark. With it in place, go to File, Export As, Export as PDF.

On export: Sign with watermark

LibreOffice’s PDF export dialogue has a Watermark section on its General tab, with a Sign with watermark box and a Text field. According to the help, it adds centred, vertical, light green text to the background of each page, and the watermark isn’t stored in the source document.

That’s handy when you need several copies of one document for different recipients: export once per recipient and change the text each time. The catch is that the help says you can’t adjust the watermark’s position, orientation or size. For a large diagonal across the content, use Format, Watermark instead. And if one of those copies is a spreadsheet exported from Excel, redact the names in Excel before it becomes a PDF.

How to watermark a PDF on a Mac with Preview

Preview has no feature called watermark, but it lets you put text on top of a PDF, and that covers most uses. Apple’s help describes it like this:

1. Open the PDF in Preview. If the markup toolbar isn’t showing, click the Show Markup Toolbar button.
2. Click the Text tool, type your text and drag the text box where you want it.
3. Use the Text Style tool to change the font, style and colour.
4. Repeat on each page that needs the watermark.

How you save is the step that matters. Apple says that saving with File, Save or File, Export leaves annotations editable, so anyone who opens the PDF can move or delete your text. To flatten them so they can’t be edited, choose File, Print, then Save as PDF. Do that with the copy you’re sending, and keep the original PDF unmarked.

Preview works page by page. That’s fine for a payslip; for a lease that runs to forty pages, Word, LibreOffice or Acrobat will save you time. And a black box drawn with the same markup tools hides nothing either: how to redact a PDF on a Mac covers the version that removes the text.

How to watermark a PDF with Acrobat

Acrobat’s watermark feature is the most complete. Adobe points out that, unlike stamps, watermarks are embedded into the page. The steps from Adobe’s help:

1. Open the PDF and select Edit.
2. In the left pane, select Watermark, then Add.
3. In the Add Watermark dialogue, under Source, choose Text for a text watermark or File for an image.
4. Under Appearance, set the opacity, rotation and size.
5. Under Position, set the vertical and horizontal placement.
6. Select OK.

The watermark settings panel also lets you adjust the font and the page range and preview the result. If you have a pile of documents to mark, Apply to Multiple Files adds the same watermark to a batch of PDFs and asks where to save them.

Removing a watermark in Acrobat

Acrobat can also update or remove watermarks, and Adobe documents removal on its own help page, for one file or several at once. That’s useful when the copy was yours and you now need it clean.

It also shows the limit of any watermark: if there’s a command to take it off, someone else can use it too. A large watermark across the content is still harder to remove without a trace than a small one in a corner, especially once the PDF has been printed and scanned again. But no watermark is impossible to remove.

That’s why Acrobat keeps redaction as a separate tool, which deletes the text instead of covering it; our guide to redacting a PDF in Acrobat Pro walks through it.

A watermark doesn’t redact: TFN, Medicare number and licence number

This is the point people mix up most. A watermarked copy still shows everything: the name, the address, the numbers. In a PDF with real text, those details can be selected and copied as though the watermark weren’t there. The watermark says who the copy was for; it doesn’t decide what goes in it.

Three Australian identifiers, plus your bank transactions, turn up on documents people watermark and send, and in each case an official source says the recipient often doesn’t need them:

Detail	Where it turns up	What the official source says
Tax file number	Payslips, tax documents for a rental or loan	The OAIC says nobody can use your TFN to confirm your identity when you rent a place or open a bank account
Medicare number	Medicare card copy for an agent	The OAIC suggests blanking out details the agent doesn’t need, and says an agent who copies, uses or discloses the document must generally blank out the identifier
Driver licence number	Licence copy for rentals, car hire, onboarding	The same OAIC page lists a driver licence number as a government related identifier
Bank transactions	Statements for a Victorian rental	Consumer Affairs Victoria lists a bank statement without transaction details as what can be asked for

Redact first, then watermark

So the right order is:

1. Work out what the recipient needs. A bank verifying your identity has to read the whole document. An agent checking your income needs the pay figure, but not your TFN.
2. Redact what they don’t need. Before the watermark, not after.
3. Add the watermark with the recipient, the purpose and the month.
4. Send the new copy, never the original.

The watermark records the purpose; redacting makes sure nothing extra travels with it. For a PDF, redact the PDF with Nonimo before you watermark it: you upload the file, we don’t keep your document, and you download a new PDF with the details replaced. If you hold TFNs for clients or staff, our guide on how to redact a TFN covers the label and the line it sits on, not just the digits.

Licence cards are a case of their own, because the card number sits in a different place depending on the state. The guide to redacting the card number on your driver’s licence shows where it is on each one.

Watermarking a copy of your ID: separate guides

The most common thing Australians watermark isn’t a contract: it’s an ID copy for a rental application, a new job or a bank. The steps for a PDF are the ones above, but each card raises its own questions, such as which number to leave readable, where the watermark goes so it doesn’t hide what the check needs, and what else to cover.

For a passport, watermark your passport copy with a line that names the application. For a Medicare card, which can list a whole family, there’s a guide to watermarking a Medicare card copy. For a licence, each state has its own page, starting with the VIC drivers licence watermark guide and the NSW licence watermark guide.

Check the copy before you send it

Open the PDF you’re actually sending, not the one on screen, and check five things:

1. The watermark is on every page. Scroll through all of them, not just the first.
2. What the recipient needs is still readable. The pay figure, the date or the reference they asked for.
3. It runs across the content. If it landed in a margin, move it to the middle.
4. The text is right for this send. If you’re reusing a document, make sure the watermark doesn’t still name the previous recipient. It happens more often than you’d think.
5. The file properties are clean. A PDF with a perfect watermark can still carry the author’s name, or a client’s name in its title field.

For that last check, use the steps to clean the metadata out of Word and PDF files, which cover Acrobat, Word, LibreOffice and the Mac.

Where watermarking a PDF fits in an office

At a real estate agency, plenty of documents carry other people’s details: payslips, bank statements and ID copies from applicants, and draft leases. A watermark with the property address and the date ties each copy to its application.

At an accounting practice, the classic use is the draft: financial statements or a tax return not yet signed off, which shouldn’t circulate as if final. A diagonal DRAFT avoids confusion with the client and with third parties.

The rule is the same everywhere: the watermark goes on a copy, the original stays clean, and anything the recipient doesn’t need is redacted first. For the documents your team puts into ChatGPT or Copilot rather than an email, Nonimo covers client names and identifiers before the text reaches an AI tool.

Sources

• Adobe, “Add watermarks to PDFs” (last updated 21 January 2026; checked 24 October 2026): definition, the difference from stamps, and Edit, Watermark, Add with Apply to Multiple Files. helpx.adobe.com
• Adobe, “Remove watermarks” (last updated 23 September 2025; checked 24 October 2026): See all tools, Edit a PDF, Watermark, Remove, for one file or several. helpx.adobe.com
• Microsoft, “Insert a watermark” and “Use a custom watermark” (checked 24 October 2026): the Windows and Mac steps, the presets, and the Word for the web limit. Insert a watermark · Custom watermark
• Microsoft, “Adjust the placement of a watermark on the page” (checked 24 October 2026): the watermark is selected by opening the header. support.microsoft.com
• Microsoft, “Remove hidden data and personal information by inspecting documents” (checked 24 October 2026): the Headers, Footers, and Watermarks category of the Document Inspector. support.microsoft.com
• LibreOffice Help, “Watermark” and “General” (PDF export) (checked 24 October 2026): Format, Watermark, its settings and limits, and Sign with watermark on export. Watermark · PDF export
• Apple, “Annotate a PDF in Preview on Mac” (checked 24 October 2026): the Text and Text Style tools and flattening annotations with File, Print, Save as PDF. support.apple.com
• OAIC, “Your tax file number” (checked 24 October 2026): a TFN can’t be used to confirm your identity when you rent a flat or open an account with a financial institution. oaic.gov.au
• OAIC, “Tenancy” (checked 24 October 2026): agents covered by the Privacy Act collect only what is reasonably necessary; it suggests blanking out ID details the agent doesn’t need, and agents must generally blank out a government related identifier, such as a Medicare or driver licence number, when they copy, use or disclose the document. oaic.gov.au
• Consumer Affairs Victoria, “Applying for a property” (checked 24 October 2026): a bank statement for a rental application is one without transaction details. consumer.vic.gov.au
• Australian Federal Police, “Apply for a National Police Certificate” (checked 24 October 2026): you scan or photocopy identity documents worth at least 100 points, and contact the AFP if you can’t meet 100 points. afp.gov.au