When a fax is delivered successfully, but sometimes the recipient's copy is missing information that was clearly visible in your original PDF - typed answers in a form appear blank, checkboxes look unticked, or comments and stamps are gone. This is almost always caused by how the PDF was created, not by the transmission itself.
Why this happens
Fax is an image-based technology. When you send a PDF, Fax.Plus converts each page into an image before transmission. This conversion renders the page content of your document.
However, a PDF can contain more than just the printed page. Interactive form fields (the fillable boxes you type into), annotations, sticky notes, stamps, and digital signatures are stored differently from regular page content, and PDF software can render a document with or without these elements. Depending on how the file was created and filled in, the conversion may render the blank form without your entries.
This is why the fax can be marked as delivered while the recipient receives a version with the filled-in information missing.
How to fix it
Before sending, flatten your PDF so that everything you see becomes a fixed part of the page itself:
- Print to PDF (recommended): Open the filled document, choose Print, and select "Save as PDF" (Mac) or "Microsoft Print to PDF" (Windows) as the printer. The resulting file is flattened. Send this file instead of the original.
- Adobe Acrobat: Use Print > Advanced > "Print as image" when creating the PDF, or save the form with the "Flatten" option if your version offers it.
- Preview (Mac): Export the document as a new PDF after filling it in.
After flattening, open the new file and check that your entries are still visible - what you see in the flattened file is what will be transmitted.
Other reasons content can be missing
- Content near the page edges: fax machines cannot print to the very edge of the page. Keep margins of at least 10-15 mm (0.4-0.6 in). See: Why did my fax come out shrunk, sideways, or cropped?
- Unusual page sizes: pages larger than A4/US Letter are scaled down, which can make small text unreadable. Re-export the document at a standard page size.
- Non-embedded fonts: if a PDF uses fonts that are not embedded in the file, some text may display or transmit incorrectly. Re-exporting the document (for example via Print to PDF) often helps in this case as well.
Still seeing missing content?
If information is missing even after flattening the document, contact our support team with:
- the original PDF you sent,
- a copy or photo of what the recipient received,
- the date, time, and recipient number of the fax.
We will review the converted document on our side and investigate further.