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Home > Guides > Fax vs Direct secure messaging
Use Direct secure messaging with partners who have Direct addresses, and keep fax as the universal fallback for everyone else. Direct is the HIPAA-ready encrypted standard built on the ONC Direct Project: email-like messages, identity-verified endpoints, encrypted end to end. Fax works with any phone line and needs no setup, which is why it still refuses to die.
| Fax | Direct secure messaging | |
|---|---|---|
| What it is | Scanned images sent over phone lines or internet fax services | Encrypted email-like messages under the ONC Direct Project standard |
| Encryption | Not encrypted on the wire; security comes from process controls | Encrypted end to end; identity-verified sender and receiver |
| Who you can reach | Anyone with a fax number | Only endpoints with a Direct address through a HISP |
| Data format | An image of a page | Structured data that can flow into the EHR, plus attachments |
| Setup | Plug in a number or use an online service | Onboarding through a Health Information Service Provider (HISP), with identity proofing |
Direct, formally Direct Secure Messaging, is a US health-IT standard that grew out of the ONC's Direct Project. It looks and feels like email: each participant has a Direct address, you compose a message, you attach files, you send. Under the surface, a Health Information Service Provider (HISP) encrypts and digitally signs each message, and both endpoints are identity-verified, so the recipient knows the message came from the claimed sender and wasn't altered in transit. The whole exchange is designed to meet HIPAA security requirements for protected health information.
Two features separate it from fax in practice. First, Direct messages can carry structured data: medications, allergies, problem lists, formatted so the receiving EHR can absorb them without retyping. A fax is an image of a page; someone still has to read it and key it in. Second, Direct runs inside a trust network. Accredited HISPs participate in the DirectTrust framework, which sets the security and identity rules, and providers find each other's addresses in a national directory. It is not a public directory you can message at will: it only works between verified members.
The honest answer is network reach. Fax works with anyone who has a fax number, and in healthcare that is still nearly everyone: small practices, nursing homes, pharmacies, insurers, durable-medical-equipment vendors. Direct only works when both sides have Direct addresses. A clinic can be fully Direct-capable and still fax half its referrals, because the other half's endpoints aren't enrolled.
Setup friction is the second reason. Getting a Direct address means onboarding through a HISP with identity proofing, which takes days to weeks. A fax line takes an afternoon. For a solo practice that sends a handful of referrals a week, the fax wins on effort every time.
Interoperability gaps keep the cycle going. Referrals, prior authorizations, and discharge summaries cross organizational boundaries constantly, and every boundary where one side lacks Direct becomes a fax boundary again. That is why fax remains the universal fallback even in health systems that use Direct heavily for transitions of care.
Use Direct for high-volume, repeat partners who are on the network: the hospital system you discharge to, the specialists you refer to weekly, the pharmacy that fills your orders. That's where structured data pays off, because the receiving side absorbs it into the EHR instead of retyping it, and where encrypted, identity-verified exchange is worth the onboarding.
Use fax for everything else: one-off referrals, small practices, insurers, vendors, and any recipient whose Direct address you can't find. Trying to force a partner onto Direct for occasional contact is more work than the relationship justifies.
Note the geography. Direct is a US framework built around HIPAA. Canadian clinics work under provincial health-privacy laws instead, and the practical channel for cross-border or Canadian referrals remains fax or the receiving province's own secure systems.
With the fax side: describe the document and the recipient's fax number to your AI assistant, review the per-fax quote with the page count verified, approve the exact total, and the fax is sent. LetterAgent faxes go to US and Canadian numbers only, and the fax service is currently in testing. LetterAgent does not offer Direct messaging; for that, your EHR vendor or a HISP is the route.
Ready to fax it? Fax with LetterAgent: describe it to your AI assistant, approve the exact quoted price, and it is sent.
LetterAgent is a working name. Prices include print, postage, and our service fee. US prices in USD, Canadian prices in CAD (Canadian prices exclude applicable sales tax, added at checkout). Currently in private testing.
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