The Short Answer
Yes, you can fax multiple documents at once, and you do not need to merge them into a single PDF first. On unofax you add up to 10 files to the same fax, put them in the order you want, preview every page and pay once. The files can be different formats, so a PDF form, a Word letter and a phone photo of your ID can all go out together. The recipient gets one fax, not three.
The rest of this post covers when sending one combined fax is the right call, how to do it, how pages are ordered and priced, and the handful of cases where splitting the job is smarter.
Why People Merge PDFs Before Faxing (and Why You Can Stop)
A physical fax machine never had this problem. You stacked the pages in the feeder and it sent them in order. Online fax services changed that by asking for a file, and for a long time most of them asked for exactly one. If your paperwork lived in three files, you had to find a PDF merger, upload sensitive documents to yet another website, download the result and only then start the fax.
That detour is where things go wrong. Pages end up in the wrong order, a photo gets left out because the merger only took PDFs, or the person gives up and sends three separate faxes that arrive at a busy office as three unrelated piles of paper.
Multi-file upload removes the step. You hand over the files as they are, and the fax service does the joining. You still see the finished document before any money changes hands.
How to Fax Multiple Documents in One Fax
- Open unofax.com on a computer or phone. There is no account to create and nothing to install.
- Add all of your documents. Drag several files onto the upload area together, or click browse and select more than one. On a phone you can pick several items from Files or Photos. Missed one? Use Add another file, up to 10 in total.
- Put the files in order. The arrows beside each file move it up or down. The list is faxed from top to bottom.
- Enter the fax number and fill in the free cover sheet if you want one.
- Preview every page. All of the files are converted and joined into one fax document, shown in sending order. This is the moment to catch a sideways scan or a page that is missing.
- Pay once and send. One payment covers the whole bundle, and one confirmation email tells you it arrived.
The multiple files guide has the full reference for the upload screen, including what each button does.
Bundles That Belong in One Fax
Most faxes that involve more than one file fall into a few familiar patterns. In each case the recipient expects the pieces to arrive together.
| Situation | Typical files | Suggested order |
|---|---|---|
| Medical referral or records request | Referral letter (Word or PDF), test results (PDF), insurance card (photo) | Letter, then results, then card |
| Rental or loan application | Signed application (PDF), payslips (PDF), bank statement (PDF), photo ID (photo) | Application first, supporting documents after |
| Tax or government response | The notice you received (scan), your reply (Word), supporting forms (PDF) | Reply, then the notice, then the forms |
| Insurance claim | Claim form (PDF), receipts (photos), repair quote (PDF) | Claim form, then evidence in date order |
| Signed contract | Signature page (scan), full agreement (PDF), ID (photo) | Whatever the other side asked for, usually agreement first |
If the office gave you a checklist, follow its order. Staff who process faxes all day work down that same list, and matching it makes your file quicker to approve. For faxes to a tax authority, our post on faxing the IRS in tax season goes into more detail.
Mixing PDFs, Word Files and Photos
The files do not need to match. PDF, Word (.doc and .docx), PNG, JPG, GIF, WebP, HEIC and TIFF are all accepted, and you can combine them however you like. Every file is converted to the same black and white fax format before sending, so the recipient sees one consistent document. The supported file formats page explains how each type is handled.
Two things are worth knowing when you mix formats:
- Photos fax better when they are scans. A phone photo of a page taken at an angle, in poor light, comes out grey and hard to read. Scanning with your phone gives a flat, high-contrast page. See how to scan a document with your phone and our tips on preparing documents for the best fax quality.
- Password-protected PDFs will not convert. Bank statements and payslips are often locked. Open the file, save an unprotected copy, and upload that.
What Order Do the Pages Arrive In?
The cover sheet, if you use one, is always page one. After that comes every page of the first file in your list, then every page of the second, and so on. Pages inside a file keep their original order, so a 12-page agreement is never reshuffled.
Because it is one transmission, the receiving machine prints the pages as one continuous job with the same header on each sheet. That is the practical difference between one fax and several: nothing from another sender can land in the middle of your paperwork.
Use the cover sheet message as a packing list, for example "Signed application (2 pages), payslips (3 pages), photo ID (1 page)". It lets the recipient confirm at a glance that everything came through. There is more on this in fax cover sheet etiquette.
What It Costs
There is no fee for adding files. A multi-file fax is charged at the same flat per-page rate as any other fax, on the combined page count. Files of 2, 5 and 1 pages make an 8-page fax. The cover sheet is free and is not counted. Current rates are on the pricing page.
Sending one fax also means one delivery to keep track of. If the line is busy, the whole fax is retried automatically for up to 24 hours. If it still cannot be delivered, every page is refunded. You are never left with half of an application delivered and the other half stuck.
Limits to Know
- Files per fax: up to 10
- Size per file: up to 100 MB
- Pages per fax: up to 300 across all files, not counting the cover sheet
You are told before you pay if you go over, so you can remove a file or split the job.
When to Send Separate Faxes Instead
One combined fax is usually the better choice, with three exceptions:
- Different recipients. Documents going to different fax numbers have to be separate faxes.
- Different timing. If part of the paperwork should arrive today and the rest next week, send two faxes and schedule the second.
- More than 300 pages. Split a long document into parts and write "part 1 of 2" on each cover sheet so the recipient knows to wait for the rest.
When a Merged PDF Is Still Useful
Sometimes you want the combined file itself, perhaps to keep a copy of exactly what you sent or to email the same pack to someone else. The free Fax Merge tool joins PDFs, scans and photos into a single fax-ready PDF and shows how each page will look when it comes out of a fax machine. You can then fax that one file, or simply keep it for your records. If you only have a single PDF to send, how to fax a PDF without a fax machine covers that case.
Frequently Asked Questions
Can I fax multiple documents at once?
Yes. Upload up to 10 files and they are sent as one fax. The recipient gets a single transmission with every page in the order you chose, and you pay once for the combined page count.
Do I have to merge PDFs into one file before faxing?
No. Upload each PDF as it is and arrange the files in the list. They are combined for you, and you see the result in the preview before you pay.
Can I fax a PDF, a Word document and a photo together?
Yes. PDF, Word, PNG, JPG, GIF, WebP, HEIC and TIFF files can be mixed freely in the same fax.
How many files and pages can I send in one fax?
Up to 10 files of up to 100 MB each, and up to 300 pages in total. The cover sheet does not count toward the 300.
Does faxing multiple files cost more than faxing one?
No. There is no per-file fee. You pay the flat per-page rate on the total number of pages, and the cover sheet is free.
Is it better to send one fax or several separate faxes?
Send one fax when everything goes to the same number and belongs together. Send separate faxes when the documents go to different numbers or the total is over 300 pages.
The Bottom Line
Faxing a stack of documents no longer starts with a PDF merger. Open unofax.com, drop in every file, set the order and check the preview. One fax, one payment, one confirmation.