Sending a fax from your phone: the one step people skip
Use the phone's document-scanner mode, not the camera. A photograph of a page is the single most common reason a faxed document arrives unreadable.
Faxing from a phone is easy and the result is often terrible, and the gap between those two facts is one setting. A fax is converted to pure black and white before it goes, so the input has to be a scan. A photograph is not a scan, and the difference does not show up until somebody at the other end phones to say they cannot read it.
Scan, do not photograph
Both iOS and Android have a document-scanner mode built into the camera or the files app. It does three things a photograph does not: it finds the edges of the page and crops to them, it corrects the angle so the page is rectangular, and it thresholds the image so paper becomes white and ink becomes black.
- iPhone: Notes → new note → the camera button → Scan Documents. Or Files → the ⋯ menu → Scan Documents.
- Android: Google Drive → + → Scan. Most manufacturers also put a document mode in the camera itself.
The shadow problem
Hold the phone so your own shadow does not fall across the page. Uneven light becomes uneven dithering, and the shadow arrives as a grey block over whatever it covered. Scanner mode corrects a lot; it does not correct that.
Then send it
- Export the scan as a PDF, not as an image. A multi-page scan should be one PDF, in order.
- Attach it to an email addressed to the recipient's fax number, or upload it in the dashboard.
- Add a cover sheet only if you are faxing an organisation — what belongs on one.
- Send, and check the confirmation rather than assuming. What a transmission report proves explains what it does and does not tell you.
Photographing a screen, and other things not to do
Three inputs produce a fax nobody can read, and all three are common on a phone: a photo of a laptop screen, a screenshot of a document scaled down to phone width, and a photo taken at an angle from across a desk. If the document already exists as a file, send the file — converting it back into a photograph loses everything and gains nothing.
What a phone cannot fix
Small grey print stays hard to read, colour still becomes black, and a photograph of a photograph is still a smear. What a fax does to a PDF covers what survives the conversion, and it applies to a phone scan exactly as it applies to anything else.