Guide
Are online fax services secure?
Short answer: a well-built online fax service is usually more private than a fax machine sitting in a shared office — but no fax is encrypted end to end, and that matters. Here is the honest breakdown.
What is actually protected
When you send a fax online, the document travels in two very different legs. The first leg is from your browser to the service, over an encrypted internet connection — the same protection as online banking. On NimbleFax the file is then held in private storage that is scoped to your account, so no other customer can retrieve it.
The second leg is the phone network, where the service dials the recipient's machine. The fax standard itself has no encryption, so this leg is not encrypted — for any provider, and for any physical fax machine. Anyone claiming otherwise is overselling.
Compared to a fax machine
A machine is often the weaker option in practice. Incoming faxes print onto a tray anyone walking past can read, they sit there overnight, and the machine's memory can retain pages. With an online service the document only opens for someone signed into the account.
The one advantage a machine has is that the document never touches a third party. If that matters more to you than the printed-tray problem, a machine is a reasonable choice.
Compared to email
Ordinary email copies your attachment through several mail servers and leaves it in mailboxes on both ends indefinitely, often synced to phones and laptops. A fax is a point-to-point transmission with no chain of copies, which is part of why healthcare, legal, and finance offices still prefer it.
That said, the recipient's printed page is the real risk with fax, and the recipient's inbox is the real risk with email. Both come down to who handles the document after it arrives.
What to check before choosing a provider
How long documents are kept. You should be able to delete a fax whenever you want. If a provider won't say how long it retains files, treat that as an answer.
Whether it is free and why. Free fax sites usually monetise something. Ads on your cover page, retained documents, or resold contact data are all common. Paying 20¢ a page is cheap certainty.
Whether your account is properly protected. Your faxes are only as private as your login. Use a unique, strong password.
Whether they promise the impossible. Any provider claiming end-to-end encrypted fax transmission is describing something the fax protocol does not support.
How NimbleFax handles your documents
Documents travel over encrypted connections and are stored in private storage that only your account can open. Every fax in your history can be deleted by you at any time. We do not place advertising on your pages and we do not sell your data — the business runs on the 20¢ a page or $12.99 a month you pay.
If you handle protected health information, read the HIPAA guide as well — compliance involves paperwork beyond encryption.
Common questions
Are online fax services secure?
A well-built one is generally more secure than a fax machine in a shared office, because documents are encrypted in transit and only the account owner can open them. The weak point in any fax, online or not, is the phone leg of the transmission, which is not encrypted by the fax standard itself.
Is online faxing safer than email?
For documents the recipient insists on receiving by fax, yes — the file is not sitting in multiple mail servers and mailboxes along the way. But fax is not magically private, so treat both with care.
Who can see my faxes on NimbleFax?
Only your account. Documents are held in private storage that is locked to your account, so another customer cannot reach your files even if they know the file name.
Are free online fax services safe?
Be careful. Many free services fund themselves by placing ads on your cover page or by retaining your documents. Read what a free service says about how long it keeps files and whether it shares data before you send anything sensitive.
Can I delete a fax after sending it?
You can delete the copy stored in your NimbleFax account at any time. Once a fax has printed on the recipient's machine, that paper copy is out of anyone's control — which is true of every fax.
Is the phone leg of a fax encrypted?
No. The fax standard has no encryption, so the transmission over the phone network is not encrypted for any fax service or fax machine. This is why regulated industries pair faxing with policies about who handles the printed page.
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Still have questions? Email support@nimblefax.com.