To fax a PDF from the iPhone Files app, touch and hold the file, tap Share and choose FaxUp, or open faxup.net/send in Safari and pick the file with Choose Files. Then enter the fax number and send.
A PDF in the Files app is the easiest thing to fax from an iPhone: it is already a clean document, so there is nothing to scan. You have two routes, and both end at the same fax.
Route 1: Share it to the FaxUp app
The FaxUp app accepts PDFs and photos shared from other apps.
- Open Files and find the document. Apple's Files app shows iCloud Drive and "On My iPhone", and can also show Google Drive, Dropbox, Box or OneDrive once you turn them on under Browse, More, Edit.
- Touch and hold the file, then tap Share.
- Choose FaxUp in the row of apps. If you don't see it, open FaxUp and add the file from inside the app instead.
- The pages open in FaxUp. Check them, crop or rotate if needed, and add a signature with Fill & Sign if the form asks for one.
- Enter the fax number, add a cover page if you need one, and send.
Don't tap Compress before sharing. Apple's Files app turns a compressed file into a ZIP, and a fax service can't open a ZIP. If the PDF is too big, use compress PDF instead, which keeps it a PDF.
Route 2: Pick it in Safari
- Open faxup.net/send in Safari.
- Tap to add a file and choose Choose Files. A file browser opens with the same locations as the Files app.
- Pick the PDF. You can add more files, up to 10, and they are sent as one fax in that order.
- Go through the preview: every page in black and white, as it will print.
- Enter the number and send.
No app needed, and the same account and credits as the app if you sign in with the same email.
Files that need a little work first
- Several separate PDFs that must arrive in a set order: merge them with merge PDF, then fax one file.
- Pages the wrong way round or out of order: fix them in organize PDF or rotate PDF.
- A form that needs filling in: use Fill & Sign in the app, or the free fill and sign PDF tool in Safari. Check whether the recipient accepts an electronic signature; some IRS forms don't.
- A paper page that isn't in Files yet: the Files app has its own Scan Documents option, and the FaxUp app's scanner makes pages tuned for fax.
Word and other documents
On faxup.net you can send Word (.doc, .docx), Excel, PowerPoint, OpenDocument, RTF, text and HTML files as they are; they are turned into PDF pages before dialling. Check the preview: a document that uses unusual fonts or very small text can look different from the original. If it matters, export it as a PDF first from the app that made it.