Quick answer
A traditional fax machine on an analogue line stops working when the PSTN is switched off on 31 January 2027. Fax can technically run over an internet connection using a standard called T.38, but it is sensitive and not reliable enough to bet a legal or clinical document on. For the small number of businesses that genuinely still need to send or receive faxes, the practical answer is a cloud fax service - a fax number that delivers to email, with no line and no machine. For everyone else, the honest answer is that the switch-off is a good reason to stop. Before you replace anything, count how many faxes you actually sent last year.
Fax is the one item on the switch-off list where the right answer is quite often "do nothing, and cancel the line". I have looked at a lot of phone bills, and a dedicated fax line is one of the most reliable places to find money being wasted - a standing charge, rising through 2026, for a machine that receives the occasional misdial and a supplier's promotional flyer. So this guide starts with arithmetic rather than technology. If it turns out you do need fax, the replacement is cheap and quick; if it turns out you do not, cancelling the line is an immediate saving. If you want us to audit which of your lines are actually doing anything, get a no-obligation quote.
Why fax stops working
A fax machine is a modem. It converts a page into audio tones, dials the receiving machine and plays them down an analogue line, and the machine at the far end reassembles the page. The whole design assumes the specific, consistent characteristics of the analogue network.
When the PSTN is switched off, that network is gone, and with it the conditions the protocol was built for. Openreach also stopped selling new analogue lines in September 2023, so you cannot order a replacement line for a fax machine even now - see our Openreach stop-sell guide. This is one of the clearer cases in the whole migration: there is no copper option to keep.
Start here: what is your fax line actually costing you per fax?
This is a two-minute calculation and it usually settles the decision.
- Find the monthly charge for the line the fax machine uses. Include line rental and any minimum charges. Remember this figure has risen through 2026 as legacy line rental went up in stages - see the WLR price rises.
- Multiply by twelve for the annual cost.
- Count the faxes you genuinely sent or received in the last year that mattered. Not junk, not misdials, not the same supplier's newsletter. Check the machine's log or journal.
- Divide.
The result is frequently uncomfortable. A line carrying a handful of real faxes a year, at 2026 legacy prices, can work out at an absurd cost per document - and that is before you count the toner, the paper and the floor space. I have seen this exercise end a fifteen-year fax habit in a single meeting.
Two things often emerge alongside it. First, some businesses find the fax line is also doing something else - feeding a card terminal, or acting as a backup voice line - so check before you cancel. Second, some find they have a fax line and no working fax machine, which happens more often than you would think. Our devices that rely on phone lines guide covers the wider audit.
The three honest options
| Option | What it is | Cost shape | When it fits |
|---|---|---|---|
| Stop faxing | Cancel the line, retire the machine, use email or a portal | Saves money immediately | Most businesses - by a wide margin |
| Cloud fax / fax to email | A fax number hosted by a provider; inbound arrives as email, outbound sent by email or web | Small monthly fee, usually per number with a page allowance | You genuinely need to send or receive faxes, or a counterparty insists |
| Fax over IP (T.38) | Your existing machine, via an adapter, over your internet connection | Adapter plus line-equivalent charges | Rarely the right answer - see below |
For almost everyone, it is the first row. For the minority who need fax, it is the second. The third exists and providers will sell it to you, but it comes with real caveats.
Why fax over IP is unreliable
T.38 is a genuine ITU standard designed to carry fax over IP networks, and it is a real improvement on trying to push fax tones through a normal voice codec. It still is not something I would rely on, for three reasons:
It is intolerant of network imperfection. Fax has no meaningful error recovery. A voice call with slight jitter or a lost packet produces a small glitch nobody remembers; a fax transmission with the same conditions fails, or produces a page with lines missing. Your office broadband is fine for voice and not necessarily fine for fax.
Both ends have to cooperate. T.38 needs support along the whole path, including the receiving side, which you do not control. If the far end is a machine on a legacy setup or a provider handling it differently, the negotiation can fail in ways nobody can debug.
Failures are quiet and confidence is misplaced. A transmission report saying "sent" is not proof the page arrived legible. For anything with clinical, legal or financial consequences, "usually works" is not a standard worth accepting.
So if you need fax reliably, use a cloud fax service, where the provider terminates the fax properly on their infrastructure rather than asking your broadband to behave like a copper line.
How cloud fax works
Straightforward, and it is why this is the recommended route:
- You get a fax number - often you can port your existing one, so nobody has to be told it changed.
- Inbound faxes arrive in a mailbox as a PDF attachment, or in a web portal.
- Outbound faxes are sent by emailing the service or uploading through the portal.
- No machine, no line, no toner, and it works from anywhere.
- Pricing is typically a small monthly fee per number with an included page allowance.
Compared with a dedicated analogue line at 2026 prices, this is normally a substantial saving as well as less hassle. It also removes a physical failure point: nobody has to notice the machine is out of paper.
One thing to check when comparing services: whether you can port your existing fax number, what happens if you exceed the page allowance, and where the received documents are stored - which matters for the next section.
The awkward truth about fax and security
Fax has an undeserved reputation as the secure option. It persists in some industries specifically because people believe a fax is safer than an email, and that belief does not hold up well.
- Fax transmissions are not encrypted. The content travels as tones over a network.
- A fax arrives on a shared machine in a shared space, where anyone passing can read it. Email at least lands in an addressed mailbox.
- Misdirection is easy and irreversible. One wrong digit sends a document to a stranger, with no recall and often no way of knowing. Misdirected faxes have been a recurring cause of reported data breaches for years, particularly where sensitive personal data is involved.
- There is usually no audit trail worth the name beyond a transmission report.
If you handle personal or sensitive data and you are keeping fax because it feels safer, that is worth revisiting properly. A secure email service or a document portal with authentication and logging is a genuinely better control, and switching to cloud fax is at least an improvement on a machine in a corridor, because documents land in a mailbox you control.
Who genuinely still needs fax
A minority, and usually not because they want to:
- Healthcare and pharmacy, where some processes and some counterparties still expect fax.
- Legal and conveyancing, where a particular firm or registry insists.
- Insurance, logistics and some public-sector suppliers, where a portal has not replaced the old process yet.
- Businesses trading internationally with partners in markets where fax remains normal.
In nearly all of these the requirement is imposed by someone else, not chosen. Cloud fax satisfies it completely - the counterparty dials a fax number and it works, and they neither know nor care that there is no machine. That is the neat resolution: you meet the requirement without keeping the line.
Before you assume the requirement is real, though, ask. A surprising number of "they only accept fax" beliefs turn out to be several years out of date, and one email to the counterparty settles it.
What to do
- Find the line the fax machine uses and its current monthly cost.
- Check the machine's log for genuine volume over the last year.
- Do the cost-per-fax sum.
- Ask any counterparty who supposedly requires fax whether that is still true.
- If you can stop: confirm the line does nothing else, then cease it and bank the saving.
- If you cannot: set up cloud fax, port the number, test it in both directions, then cease the line.
- Either way, cease the line. This is the step that gets forgotten, and it is the whole point of the exercise.
Our switch-off cost guide covers the rest of the migration budget, and the switch-off deadline guide sets out where fax sits in the running order - which is near the bottom, behind anything safety-critical.
The bottom line
Fax over copper ends on 31 January 2027 and there is nothing like-for-like to buy. Do the arithmetic before the technology: a dedicated fax line at 2026 prices, carrying a handful of real documents a year, is one of the easiest savings in a business's telecoms budget. If you genuinely need fax, cloud fax gives you a number that delivers to email for a fraction of the cost, and you can usually keep the number. Do not build the replacement on fax over IP unless nothing important depends on it.
If you are not sure which of your lines does what - and most businesses are not - that is exactly what our audit is for: get a no-obligation quote or call 0333 006 9399. We would rather tell you to cancel a line than sell you a replacement for it.
Getting unknown calls on a business line? Our free UK phone number checker shows which network or provider Ofcom allocated any number to, and whether the range is in service — no sign-up.
Frequently asked questions
Can you still fax after the PSTN switch-off?
Not with a traditional fax machine on an analogue line - that stops working after 31 January 2027, and new analogue lines have not been orderable since September 2023. You can still send and receive faxes using a cloud fax service, which gives you a fax number that delivers documents to email without any line or machine.
What replaces a fax machine after the switch-off?
For most businesses, nothing - they stop faxing and cancel the line. For those who genuinely need it, a cloud fax service is the practical replacement: a hosted fax number, inbound faxes arriving as PDFs by email, and outbound sent by email or a web portal.
Does fax work over VoIP or broadband?
Technically, using a standard called T.38, but it is not reliable enough to depend on. Fax has almost no error recovery, so jitter or packet loss that would barely affect a voice call causes failed or corrupted transmissions - and both ends of the connection have to support it properly. Use a cloud fax service instead.
Can I keep my fax number?
Usually yes. Fax numbers are ordinary phone numbers and can generally be ported to a cloud fax provider, so anyone who has your fax number on file can carry on using it. Confirm portability with the provider before you commit, and never cease the old line before the number has moved.
Is cloud fax cheaper than a fax line?
Almost always, and often dramatically so. A dedicated analogue line carries a monthly standing charge that rose in stages through 2026, whereas cloud fax is typically a small monthly fee per number with an included page allowance - plus you stop buying toner, paper and machine maintenance.
Is fax more secure than email?
No, despite the reputation. Fax transmissions are unencrypted, documents arrive on a shared machine where anyone can read them, a single mistyped digit sends a document irretrievably to a stranger, and there is no meaningful audit trail. Misdirected faxes have long been a recurring cause of reported data breaches. Secure email or an authenticated document portal is a better control.
Do I still need fax if a supplier insists on it?
You need a fax number, not a fax line or a machine - and cloud fax provides exactly that, invisibly to them. It is also worth checking whether the requirement is still real, as plenty of "we only accept fax" policies are several years out of date and one email will confirm it.