How to eFax | Send Faxes Without a Machine

eFax lets you send and receive faxes over the internet using email or a web portal — no fax machine or phone line required.

How to eFax comes down to a simple sequence: upload a document to an online service, enter the recipient’s fax number in full international format, and click send. The document arrives on the recipient’s fax machine or eFax inbox just like a traditional fax, but you never touch a phone line or buy toner. The whole process takes about a minute from any computer or phone.

What Is eFax, and How Does It Work?

eFax replaces the physical fax machine with a cloud-based service that converts digital documents into fax signals and transmits them over the phone network. You upload a PDF, Word document, or image through a web portal, mobile app, or email gateway, and the service handles the rest. No dedicated phone line, no fax hardware, no consumables.

The recipient sees the fax arrive on their machine exactly as if it came from a traditional fax unit. Most eFax services also offer inbound fax numbers so you can receive faxes the same way — entirely without paper.

How to Send an eFax — The Basic Steps

Every eFax service follows the same five-step workflow. The exact button labels vary by provider, but the sequence is consistent across web portals, mobile apps, and email gateways.

Step 1: Sign Up for an eFax Account

Register with your email address. Some providers require a phone number for verification; others let you start with just an email. Fax.Plus offers a free eFax account with no credit card needed, making it the easiest way to test the process. Other services like iFax provide free trials, while eFax.com requires a paid subscription starting around $14 per month.

Step 2: Prepare Your Document

Save your file in a supported format. Most services accept PDF, Word (.doc/.docx), Excel (.xls/.xlsx), PowerPoint (.ppt/.pptx), JPG, PNG, GIF, TIFF, and TXT. Multiple attachments are usually supported and are sent in the order you attach them. The hard rule: if a file can’t be printed, it can’t be faxed — video formats (.avi, .mpeg) and audio files won’t work.

Step 3: Enter the Recipient’s Fax Number Correctly

Format the number in full international format: country code plus area code plus local number, with no hyphens, parentheses, or spaces. For a US number like (608) 555-1234, enter +16085551234 (the +1 is the US country code). Fax.Plus’s free eFax guide confirms this format and shows how to avoid the most common number-entry errors. Omitting the country code is the single most common reason a fax fails to go through. Some providers also accept local numbers using just the last 7 digits when dialing within the same area code.

Step 4: Add a Cover Sheet (Optional)

Most services let you attach a cover sheet with a subject line and a brief message. This step is optional but recommended for professional or legal correspondence. The cover sheet is usually a toggle option inside the send window.

Step 5: Send and Confirm

Click the send button. The service processes the file and transmits it as a fax signal. You receive a confirmation email or in-app notification within a few minutes. Always check this confirmation — a failed fax usually comes with an error code that tells you exactly what went wrong: a bad number, an unsupported file, or a busy recipient line.

eFax Methods Compared

The table below shows the most common eFax options and their key trade-offs so you can pick the right one for your situation.

How to Format a Fax Number Correctly

Number formatting varies by call type and delivery method. This reference covers the most common scenarios you’ll encounter.

Common eFax Mistakes to Avoid

A few small errors cause most failed faxes. Each one is easy to fix once you know what to look for.

• Missing country code. The most frequent cause of failed delivery. Always include +1 for US numbers.
• Incorrect number format. Hyphens, parentheses, and spaces confuse the system. Strip them all out before sending.
• No attachment. An empty email or a send command with no file attached produces nothing.
• Wrong sender email. If you use the email method, the message must come from the email address registered with your eFax account.
• Unsupported file type. Video and audio files cannot be converted to fax format. Stick to PDFs, Office documents, and standard image formats.
• Multiple attachments through a portal that only accepts one. CallHarbor’s portal accepts one file per fax — use the email method if you need to send more.
• Using Windows Fax & Scan as eFax. That tool requires a physical fax modem and a telephone line; it is not an internet-based service.

Quick-Reference eFax Checklist

Before you hit send on your next eFax, run through this checklist to make sure everything is set up correctly.

1. Account ready. You are signed in with a valid email address linked to your eFax service.
2. File prepared. Your document is in a supported format — PDF, Word, or an image file.
3. Number formatted. The recipient’s number uses full international format with no hyphens, parentheses, or spaces.
4. Cover sheet added. Included if the correspondence requires one for clarity or professionalism.
5. Confirmation checked. You verify delivery via email or app notification after sending.

Follow this sequence and your eFax will reach its destination on the first try — no paper, no phone line, no second attempts needed.