How to turn a pile of photos into one tidy PDF

You photograph six pages of a document with your phone, or a stack of receipts, or the front and back of an identity card. Then the form tells you to upload a single PDF, and you have six JPGs.

Combining them is straightforward. Doing it in a way that gets accepted first time takes slightly more care, and the difference is usually why one submission sails through and another comes back.

Why they insist on one PDF

It is not arbitrary. A single document arrives in a fixed order, opens in one window, prints as one job, and can be filed as one item. Twelve loose images arrive in whatever order the upload happened to produce, and whoever processes them has to work out which is page one.

PDF also preserves page order as part of the file, which image files cannot do. Rename JPGs and the order changes. Put them in a PDF and page three stays page three permanently.

Get the order right before you start

This is where most of the pain lives. Phone cameras name files by timestamp, so if you photographed the pages out of sequence, or retook page four after finishing, the file order will not match the document order.

1. Photograph pages in order, front to back, without going back to retake until the end.
2. If you did retake one, check its position before combining rather than after.
3. Where a tool lets you reorder before converting, use it and read the sequence once from top to bottom.
4. Open the finished PDF and page through it before uploading anywhere.

That final check takes fifteen seconds and catches the single most common rejection reason, which is a document assembled in the wrong order.

Orientation and size

Photographs taken in portrait sometimes arrive rotated, because the rotation is recorded as metadata rather than applied to the pixels, and not every tool reads it. Fix rotation before combining, not after, since correcting it inside a PDF is more awkward.

Mixing portrait and landscape pages in one document is legal but looks careless in a formal submission. If some pages are sideways, rotate them so the whole document reads in one orientation.

Size matters as well. A phone photograph is typically several megapixels, and six of them combine into a file that can easily exceed twenty megabytes. Most portals cap uploads well below that, so expect to compress the result.

Making the pages actually readable

A combined PDF is only useful if the person receiving it can read it. The failures here are the same ones that spoil any document photograph.

• Shadows falling across the page, usually your own, from a light behind you
• The page photographed at an angle so it appears as a trapezoid
• Fingers or the surrounding table included in the frame
• Glare from a glossy page or a laminated card under direct light
• Focus locked on the table rather than the paper

Daylight from a window, the camera held directly above the page, and the page filling the frame solve nearly all of these. It is worth reshooting a bad page rather than submitting it, because a rejected application costs far more time than a second photograph.

A note on identity documents

When combining photographs of passports, licences or bank cards, remember that the resulting PDF contains full-resolution images of them, and that it will sit in someone's inbox and their document system for a long time.

Send it only through the channel the organisation specified, avoid emailing it where a portal exists, and do not keep the combined file in a shared folder afterwards. If the form asks only for the front of a card, do not include the back with the security code on it.

It is also worth using a tool that processes images in your browser rather than uploading them to a server, since for identity documents the safest upload is the one that never happens.