How to Send a Fax from Your App: The 2026 Fax API Guide

Why Fax Still Shows Up in Product Requirements

Over 17 billion faxes are sent every year. Healthcare, government, legal, and financial services all depend on fax for document transmission. If your app touches any of those industries, fax is not optional. It is a compliance requirement.

HIPAA requires covered entities to use "reasonable and appropriate safeguards" when transmitting protected health information. Fax has been an accepted method since the original 1996 regulations. Email has not. That single fact keeps fax alive in every hospital, insurance company, and pharmacy in the country.

The IRS, Social Security Administration, and most state agencies accept fax but not email attachments. Courts require faxed filings in many jurisdictions. Real estate closings still use fax for signed documents. The pattern is clear: anywhere that compliance and legal weight matter, fax is the channel.

The Old Way: Twilio, SOAP, and Pain

For years, the go-to developer option was Twilio's Programmable Fax API. It worked. It was not pretty. You needed to provision a fax-capable number, manage media URLs, handle callbacks for status updates, and navigate their pricing tiers. But it got the job done.

Then Twilio deprecated it. The Programmable Fax API is gone. If you search their docs today, you will find a deprecation notice and a suggestion to use a third-party provider. That left a gap in the market.

The alternatives are not great. Most fax APIs are wrappers around legacy infrastructure built in the 2000s. You get SOAP endpoints, XML payloads, multi-step authentication flows, and pricing models designed for enterprise sales calls. For a developer who just needs to send a fax from a Node.js app, it is overkill.

The FaxDrop API: One Endpoint, Multipart Upload

FaxDrop's approach is simple on purpose. There is one endpoint: POST /api/send-fax. You send a multipart form with the recipient's fax number and a file attachment. FaxDrop handles the rest: conversion, transmission, delivery confirmation.

Supported file types include PDF, DOCX, JPEG, and PNG. The API accepts files up to 10MB. Authentication uses a simple API key passed as an X-API-Key header. No OAuth flows, no token refresh, no session management.

curl -X POST https://www.faxdrop.com/api/send-fax \
  -H "X-API-Key: YOUR_API_KEY" \
  -F "to=+15551234567" \
  -F "file=@document.pdf"

import requests

resp = requests.post(
    "https://www.faxdrop.com/api/send-fax",
    headers={"X-API-Key": "YOUR_API_KEY"},
    files={"file": open("document.pdf", "rb")},
    data={"to": "+15551234567"},
)
print(resp.json())

const form = new FormData();
form.append("to", "+15551234567");
form.append("file", fs.createReadStream("document.pdf"));

const res = await fetch(
  "https://www.faxdrop.com/api/send-fax",
  {
    method: "POST",
    headers: { "X-API-Key": "YOUR_API_KEY" },
    body: form,
  }
);
console.log(await res.json());

That is the entire integration. No SDK to install. No webhooks to configure for basic usage. The response includes a fax ID and status. Poll the status endpoint or check the dashboard if you need delivery confirmation.

HIPAA Compliance Out of the Box

If you are building for healthcare, compliance is not a feature request. It is table stakes. FaxDrop uses Sinch as its fax carrier. Sinch signs Business Associate Agreements and maintains SOC 2 certification. That means the entire transmission chain, from your API call to the receiving fax machine, is covered.

Documents are encrypted in transit. They are not stored permanently on FaxDrop's servers after delivery. The cover page (available to subscribers) includes a confidentiality notice. For healthcare apps that need to transmit prescriptions, lab results, referrals, or insurance forms, this is the path of least resistance.

For a deeper look at fax and HIPAA, read our full HIPAA compliance breakdown.

AI Agents Need Fax Too

Here is something most fax providers have not figured out yet: AI agents are about to become the primary senders of faxes.

Think about an AI medical billing agent that processes claims. When a payer requires faxed documentation, the agent needs to send it automatically. An AI legal assistant filing court documents. An AI tax preparer submitting forms to the IRS. These are not edge cases. These are the near-term future of every industry that still uses fax.

A REST API with a single endpoint is exactly what an AI agent needs. No browser automation. No multi-step forms. One HTTP request with a file and a phone number. FaxDrop is also building an MCP server so AI agents using the Model Context Protocol can discover and call the fax tool natively.

Pricing That Makes Sense for Developers

FaxDrop offers two free faxes per month with no signup required. For regular use, the Starter plan is $4.99/month for 50 fax credits. The Pro plan is $9.99/month for 150 credits. Additional credits can be purchased as needed.

Compare that to enterprise fax APIs that charge setup fees, monthly minimums, and per-page rates that add up fast. FaxDrop's pricing is transparent and posted on the pricing page. No sales call required.