The invoice came as a PDF: why the photos inside it cannot be checked, and what to ask for

A lot of contractor invoices arrive as one tidy PDF: the line items, the total, and the “before” and “after” photos pasted in underneath. It is convenient for everyone. It is also the one format in which the photos have the least to say for themselves.

Every other article on this site rests on one idea: the original photo file carries a record the camera wrote, such as the phone model, the exposure and the time on the camera clock. A photo pasted into a document is not that file any more. So we tested what is left.

What we measured

We took one photograph straight off a Samsung Galaxy Z Fold7. Our checker reads it as a Camera Original: it names the phone, the capture settings are intact, and the camera clock reads 10 December 2025 at 15:30, with its time zone recorded.

We placed that photo on a page and turned the page into a PDF with Chrome’s own PDF printing, the engine behind Print, then Save as PDF, in the browser. Then we pulled the picture back out of the PDF and checked it again.

• The picture inside the PDF was no longer a JPEG. It was stored as plain pixels, with no place in it for camera data at all.
• Nowhere in the whole PDF did the words “samsung” or “Fold7”, or the camera’s date, appear.
• The only name the PDF did record was the software that made the PDF. That describes the document, not the photo.

So in this case the photo came out with nothing to check. That is one photo and one route. We have not tested Word, Google Docs, QuickBooks or any invoicing app, and some programs may keep more of the original inside the PDF. We do not know which ones, so we will not guess. What the test shows is that you cannot count on it, and a check you cannot count on is not a check.

What a PDF’s own details tell you

A PDF usually records the program that made it and the date the document was created. Neither is about the photos. A PDF made on the 14th can hold a photo taken on the 14th, a photo taken two years ago, or a picture that was never taken at all. The document date answers “when was this invoice put together”, which is not the question you have.

What our checker does with a PDF

It says Not Read. It does not open PDFs, so the photos inside have not been checked, and it says so rather than implying it looked.

We should be plain about a mistake here. Until 24 September 2026, a PDF dropped onto the checker got an answer it had not earned. Usually it was “Can’t Verify”, with a line saying the file had been re-encoded or screenshotted, which is a claim about a file we never opened. And if the invoice’s own text happened to name a chat tool, such as “drafted with Gemini”, it could be labelled AI Generated, because the check that looks for a generator’s name was reading the document’s words, not a picture’s. Both are fixed. A PDF now reads Not Read, whatever is written in it.

Taking a screenshot of the photos in the PDF does not help either. A screenshot is a new picture made by your computer, and it reads Can’t Verify, which tells you nothing about where the original came from.

What to ask for instead

You do not need the contractor to stop sending PDFs. You need the photos as well, as files.

1. Ask for the photos attached separately, in the same email as the invoice, as the original files from the phone. Not screenshots, and not sent through a messaging app, which usually rebuilds pictures too. The article on getting originals is written for tenants, and the same steps apply to a vendor.
2. Put it in the vendor terms, once, rather than asking invoice by invoice. Something like: “Invoices that include photos must also attach each photo as the original image file from the device that took it.” This is not legal advice; fit it to your own agreements.
3. Check the files together with last month’s. Our checker reads each file’s camera data and marks any two files that are identical, which is how you catch one photo sent for two jobs. The invoice article covers what an “after” photo can and cannot prove.
4. If the originals never come, go and look. A vendor who cannot send a file they say they took is telling you something, but it is a reason to see the work, not proof that anything is wrong. Plenty of honest people have never been asked for an original file before.

The limits, stated plainly

• We measured one photo through one route, Chrome’s Save as PDF. Other programs were not tested, and some may keep more.
• Even an original file with camera data is not a guarantee. Camera data can be edited, and a photo can be real and still be of a different unit. It is corroboration, not proof.
• A photo with no camera data is not a fake. It is a photo that cannot vouch for itself.
• Our checker gives no confidence score and does not judge a picture by looking at it. It reads what is in the file, in your browser, and uploads nothing.

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ImposterShield reads the evidence inside image and video files. It runs in your browser and uploads nothing. If a file has been stripped, it says so. If it has not read a file, it says that too.