Every expense system wants the same thing and almost never says it clearly: one PDF, receipts in a sensible order, each one legible. What people submit instead is fourteen phone photos attached individually, which is why claims come back.
The quick version
If your photos are PNG, or you screenshotted email receipts, use PNG to PDF instead. iPhone photos saved as HEIC need a pass through HEIC to JPG first.
Everything runs in your browser, which matters here — receipts carry card details, addresses and sometimes partial account numbers.
Order them to match the claim form
This is the difference between a claim approved in one pass and one that comes back with questions.
Whoever reviews your claim is reading a spreadsheet with line items and a PDF with receipts, and trying to match them up. If your receipts are in the order the photos happened to sort, that matching is their problem to solve, and they will push it back to you.
Order the receipts to match your expense lines. If the form lists them by date, order by date. If by category, group by category. Thirty seconds of dragging thumbnails saves a round trip.
Photograph them properly
Most rejected receipts are rejected for legibility, not for content.
Use your phone's document scanner, not the plain camera. Notes on iOS and Google Drive on Android both have one. It flattens perspective, crops to the receipt edge and boosts contrast — the result is smaller and far more readable than a raw photo.
Flatten the receipt first. Thermal receipts curl. A curled receipt photographs with a blur band across the middle, usually right where the total is.
Get even light. Photograph on a plain surface near a window. Overhead light directly behind you casts your own shadow onto the receipt.
Include the whole thing. Merchant name, date, itemised lines, total, and payment method. Cropping tightly to the total is the single most common reason a receipt gets queried.
What reviewers actually check
Worth knowing, because it tells you what must be legible:
If those five things are crisp, the rest can be imperfect.
Keeping the file size sensible
Fourteen phone photos at full resolution makes a PDF of 30MB or more, and plenty of expense systems cap uploads at 10MB.
Run the finished PDF through the compressor targeting 5MB or so. Receipt photos compress well — they are high-contrast text on plain backgrounds. Then check the five things listed above are still readable.
Better still, use a document scanner app at capture time. A scanned receipt is a few hundred kilobytes to begin with, so fourteen of them make a PDF that needs no compression at all.
One PDF per claim, not per month
A practical convention that avoids trouble: build one PDF per expense claim, matching the claim you are submitting. Bundling three months of receipts into one file means that when finance queries a single line, you are both hunting through forty pages to find it.
If you have already built a large bundle and need one receipt out of it, Split PDF extracts individual pages.