By Michael Chen · Published March 27, 2025 · Updated March 15, 2026 · 7 min read
Someone just asked you to send them a fax. You open your mouth to give your fax number — and draw a complete blank.
It happens more often than you'd think. How to find your fax number depends entirely on what kind of fax setup you have. This guide covers every scenario: online fax accounts, HP printers, Brother printers, Canon, and Epson — plus two fallback methods that work on any machine.
The Key Concept: Your Fax Number Is a Phone Number
Before diving into the steps, one thing to understand:
A fax number is simply the telephone number of the phone line connected to your fax machine.
It is not a separate ID assigned to the printer. It is not printed on a sticker on the machine. It is whatever phone number belongs to the landline jack the machine is plugged into.
This matters because if you never set up your fax number in the printer's menu (many people skip this step), the printer itself won't know its own number — even though calls can still come in on that line.
The easiest check
If you know the phone number of the landline your fax machine is plugged into, that is your fax number. Call it from your cell phone — if the fax machine rings and screams at you, you found it.
Method 1: Online Fax Service (mFax, eFax, etc.)
Difficulty: Very Easy — 30 seconds
If you use an online fax service, your number lives in your account dashboard — no printer menus involved.
Finding Your Number on mFax
Log in to your account
Go to mFax.to and sign in. Your fax number is displayed prominently on the main dashboard, usually in the top navigation bar or in the "My Numbers" section.
Check Settings if it's not on the dashboard
Navigate to Settings → Numbers. All virtual fax numbers assigned to your account are listed here.
Need a number? Get one in 30 seconds
If you don't have a number yet, click Get a Fax Number and choose a local area code or toll-free number. It is ready to receive faxes immediately — no hardware, no phone line required.
Advantage of online fax
With mFax, you always know your fax number because it's right there on the screen. No digging through printer menus, no calling test lines, no asking IT.
Method 2: HP Printer
Difficulty: Medium — 2 minutes
HP multifunction printers (OfficeJet, LaserJet Pro, ENVY) store the fax number in the fax header settings if it was entered during initial setup.
Access the Setup menu
On the printer's control panel, press the Setup button (it looks like a wrench or gear icon, depending on your model).
Navigate to Fax Setup
Select Fax Setup (or Basic Fax Setup on some models). If you have a touchscreen, tap through the menu until you see fax-related options.
Open Fax Header settings
Select Fax Header. You will see two fields: Fax Header Name (usually your name or company) and Your Fax Number. The number in the second field is your fax number.
If the field is blank
If no number is listed, it was never entered during setup. Use one of the two universal methods at the bottom of this guide to discover the actual line number, then enter it here for future reference.
HP OfficeJet 4650 and similar models
On some HP models, the Fax Header is under Setup → Fax → Fax Header rather than Fax Setup. The path varies slightly by model but the field name is always "Your Fax Number" or "Fax Number."
You can also access fax settings through HP's Embedded Web Server (EWS):
- Find your printer's IP address: Setup → Network → View Network Status
- Type that IP address into any web browser on the same network
- Go to Fax → Basic Fax Settings — your fax number will be listed there
Method 3: Brother Printer
Difficulty: Easy — 1 minute
Brother calls the fax number the Station ID. This is what gets printed at the top of every fax you send.
Press Menu
On the Brother printer's keypad, press the Menu button.
Navigate to Initial Setup
Use the arrow keys (or number keys) to select Initial Setup and press OK.
Select Station ID
Select Station ID and press OK. Then select Fax.
Read your number
The fax number entered for this machine is displayed. If it shows blank or a placeholder, use the universal methods below.
For Brother models with a touchscreen (newer MFC series):
Press Settings → All Settings → Initial Setup → Station ID → Fax
The path is the same concept, just navigated via touchscreen instead of arrow keys.
Method 4: Canon Printer
Difficulty: Medium — 2 minutes
Canon stores fax information in the User Data Settings or via the Fax Setup Guide.
Via the Fax Setup Guide
Press Menu on the control panel
Tap or press Menu, then select Fax Settings.
Select Fax Setup Guide
Choose Fax Setup Guide → Set Up Now. This walks you through all fax settings including the registered fax number.
Read the registered fax number
On the screen that asks for the fax number, the currently stored number (if any) will appear. Note it down.
Via the Printer Information page
If your Canon printer is networked, you can access fax settings from a computer:
- Open a browser and type the printer's IP address (found under Settings → Device Settings → TCP/IP Settings)
- In the Remote UI, click Printer Information
- Navigate to Fax Settings to view the registered line number
Canon models vary significantly
Menu paths differ across Canon PIXMA, MAXIFY, and imageCLASS lines. If the paths above don't match your screen, look for TX Settings → User Data Settings → Register Unit Tel. Number — that is where the fax number is stored on many Canon models.
Method 5: Epson Printer
Difficulty: Medium — 2 minutes
Epson stores fax settings under Fax Settings → Basic Settings.
Open Settings from the home screen
On the printer's touchscreen, tap Settings (the gear icon).
Navigate to Fax Settings → Basic Settings
Tap Fax Settings, then Basic Settings. Look for Header or Your Phone Number.
View the stored number
The number displayed under Your Phone Number is the fax number stored in the machine's settings — if it was entered during the Fax Setting Wizard setup.
Alternatively, run the Fax Setting Wizard again:
- Tap Settings → Fax Settings → Fax Setting Wizard
- Step through the wizard — it will show any previously stored fax number in the relevant field
- You can cancel without saving if you just wanted to view the number
Two Universal Methods (Any Machine)
These work regardless of brand or whether the number was ever entered in the printer menu.
The "Call It" Method
This is the fastest and most reliable way to confirm your fax number on any physical machine.
- Use your mobile phone to call what you believe the fax machine's phone number is
- If the fax machine rings and then emits that distinctive screeching tone — you have the right number
- If a person answers, you have the wrong line
- If nothing happens, the phone line may not be active
Don't know the number to try? Check recent phone bills for that line, ask your IT department, or check with the telephone company. They can tell you what number is assigned to a specific jack.
The "Header Trick" Method
Every fax machine prints a header at the very top of each outgoing fax — and that header usually includes the sender's fax number.
- Send a test fax to a free fax test service or a colleague's machine
- Look at the received fax. At the very top, you'll see a line like:
FROM: (555) 867-5309 DATE: 03/15/2026 - The number in the FROM field is your fax number
If the header shows no number (just a name or nothing), it means the Station ID / Fax Header was never configured on your machine. In that case, use the "Call It" method instead.
What If Your Printer Has No Fax Number?
Two possible reasons:
1. The printer is not connected to a phone line.
A printer connected only to Wi-Fi and power cannot receive faxes. It has no fax number because it has no phone line. Standard printers (inkjet or laser) that lack a telephone jack cannot fax at all without an online service.
2. The fax number field was never filled in.
The printer may be physically connected to a phone line but no number was entered during setup. The machine can still send and receive faxes — it just won't print its own number in the header. Use the "Call It" method to find the actual line number, then enter it in the printer's fax header settings.
No phone line? Switch to online faxing.
If your office no longer has a dedicated landline, you don't need one. mFax gives you a virtual fax number that works entirely over the internet — no phone jack, no hardware. You get a real, dialable fax number in under a minute.
Summary: Where to Look by Setup Type
| Your Setup | Where to Find Your Fax Number |
|---|---|
| mFax or online fax service | Dashboard → Settings → Numbers |
| HP printer | Setup → Fax Setup → Fax Header → Your Fax Number |
| Brother printer | Menu → Initial Setup → Station ID → Fax |
| Canon printer | Menu → Fax Settings → TX Settings → User Data Settings |
| Epson printer | Settings → Fax Settings → Basic Settings → Your Phone Number |
| Any physical machine (fallback) | Call the line from your cell phone — if it screams, that's your number |
| Any physical machine (fallback 2) | Send a test fax → read the FROM line in the printed header |
Skip the Hunt — Get a Fax Number in 30 Seconds
If you're tired of digging through printer menus and asking IT what your fax number is, the simplest fix is switching to an online fax service.
mFax gives you a dedicated local or toll-free fax number that you can see, share, and manage from your phone or computer — no fax machine, no phone line, no mystery.
Over 5 million people use mFax to send and receive faxes without ever touching a fax machine. Try it free — your number is waiting.