How to Scan Receipts for Expense Reports With Your Phone

Thermal receipts fade, curl, and photograph badly by default. Here is how to get a clean, legible, properly cropped scan every finance department will actually accept.

Receipts are the worst-behaved paper you’ll ever try to scan: thin, curling stock, faded thermal print that gets fainter every week it sits in a wallet, and a habit of arriving in a crumpled stack right before an expense report is due. A quick photo usually isn’t good enough for what a finance system expects — here’s what gets a result that actually holds up.

Why a plain photo often gets rejected

A casual phone photo captures the receipt at an angle, with background clutter (a desk, a bag, other papers) around the edges, and under whatever lighting happened to be available — shadows and glare included. Some expense systems reject submissions outright if the amount or vendor name isn’t clearly legible, which a photo with any of those problems risks being.

Scan instead of photograph

Scan to PDF is built for exactly this gap between “photo” and “scan”: it captures the receipt through your phone’s camera, then automatically crops to just the paper’s edges and cleans up the result — no separate scanner needed, no app install.

Use Black & White mode for a faded thermal receipt. This mode pushes for high contrast, which is precisely what a receipt that’s lost half its ink needs — it exaggerates the difference between the (weak) printed text and the paper background, often recovering legibility that looks close to unreadable in a normal color photo.

Use Grayscale for a receipt with a stamp, logo, or handwritten note you want to keep readable with its natural shading, rather than pushed to stark black and white.

Flatten it out first. A curled receipt casts a shadow across itself and distorts the crop. Press it flat under a book for a minute, or hold it against a flat surface while capturing, rather than shooting it as it naturally curls.

Combining a whole stack into one file

Finance departments generally want one PDF per expense report, not fifteen separate attachments. Scan to PDF combines up to 30 captures into a single PDF, one receipt per page, in the order you scan them — capture the whole stack in one session, reorder afterward if a couple ended up out of sequence, and download one file.

Sort as you go, not after. Scan receipts in the same order your expense line items will appear, and matching them to the report afterward takes seconds instead of a search.

Before you submit

  • Zoom in on the total and date in the finished PDF before submitting — the two fields most expense systems actually check, and the two most likely to be affected if a thermal receipt was already faded before you scanned it.
  • Keep the physical receipt until reimbursement clears, regardless of scan quality — a policy question for your finance team, not a technical one, but worth doing as standard practice.

After scanning

  • Compress the finished PDF if a large batch of receipts produces a bigger file than your expense system accepts
  • Reorder pages if a few receipts ended up out of sequence after scanning the whole stack
  • Lock it with a password if the report includes anything you’d rather not have openly readable in transit

Ready? Try the free Scan to PDF tool now — no sign-up, no watermark, and your files are never stored.