End of copper: your business line moves to SIP

Daniel Platteau

Updated on 27 October 2026.

Copper is disappearing, not the landline

Every year, someone announces the death of the landline. And every year, the customer with a real problem picks up the phone. They do not fill in a form: they call the number on your website, your invoice or your van.

What is disappearing is the copper wire. In Belgium, Proximus is taking it out of service wherever fibre has been rolled out. The principle, described by the regulator BIPT in 2023: copper is switched off about five years after fibre is deployed. The first zone, around Boulevard Anspach in Brussels, was switched off at the end of 2022, and the pace has picked up since. There is no national date: Proximus gives notice one year before (no new products on copper), then three weeks before (slower services, outgoing calls limited to emergency numbers), then cuts everything, including phone and alarm. Businesses can ask for the date for their address on 0800 33 500.

Changing operator does not protect you if the new operator rents the same wire: Scarlet, edpnet and the other DSL providers use Proximus copper. The day it is cut in your street, it is cut for everyone.

Elsewhere, it is already done: in Finland, Elisa made the last analogue call on its copper network on 30 June 2026, after almost 150 years of landline service.

What does not change is your number. Your 02, 04, 065 or 081 simply runs over the internet instead of a dedicated wire. That is where SIP comes in.

Why keep a landline number in 2026

• Trust. A geographic number says "we exist, we have an address". A mobile number on a €15,000 invoice looks less serious, like it or not.
• Continuity. The number belongs to the company, not the employee. When a colleague leaves, her clients do not have her private mobile in their contacts.
• Several people, one number. A call that rings three colleagues, then goes to voicemail or a colleague on duty: impossible to do properly with a plain mobile.
• History. Who called, when, how often, who answered. Essential as soon as you are more than two.
• The channel for urgent matters. As soon as a request is urgent or complicated, the phone remains the channel customers ask for.

The landline is not a relic: it is your company's voice address. The real question is which technology to run it on.

SIP: the protocol that simplified everything

SIP (Session Initiation Protocol) is the standard that sets up calls over a computer network. For voice, it is what SMTP is for email: an open standard that everyone speaks.

A SIP trunk is your "line" at the operator, delivered over the internet: your numbers, your simultaneous calls, the connection to the public phone network. No dedicated cable, no proprietary box.

What really matters to a manager:

1. Independence. Your operator, your phone system and your handsets can come from three different suppliers. If one raises prices or closes, you switch without throwing everything away.
2. Remote work without hacks. A colleague at home answers with the company number, from a PC or smartphone.
3. Business continuity. Internet down at the office? Calls switch automatically to mobiles. A cut copper line redirects nothing.
4. Growth without works. Three new hires, a second site, a Dutch-language number: these are settings, no longer projects.

Points to watch:

• Quality depends on the connection. Voice needs little bandwidth, but a stable connection. A router that gives voice priority makes a real difference, and a 4G/5G backup connection is cheap insurance.
• Call fraud. A badly configured SIP system exposed to the internet is a classic target: attackers log in to make thousands of calls to premium-rate numbers abroad. The bill comes in very real euros. See also our article on connected devices exposed to the internet.
• 112. Emergency services must be able to locate the caller: check the address linked to each number, especially for remote work.
• "Hidden" devices on copper. Alarm, lift transmitter, old fax, personal alarm service: many still use an analogue line. List them before the switch-off.

The three main families of solutions

The cloud phone system (hosted). The operator or vendor hosts everything; you pay a subscription per user and plug in phones or install an app.

• For whom: most SMEs of 2 to 50 people, especially without in-house IT.
• Advantages: nothing to maintain, automatic updates, quick start.
• Drawbacks: monthly cost that rises with the number of users, dependence on the supplier, voice data hosted with them (check where).

The on-site IP phone system (or on your server). A software phone system on a small server or virtual machine, connected to a SIP trunk.

• For whom: companies that want control of their data, have particular needs or a trusted IT provider.
• Advantages: low recurring cost, customisation, data stays with you.
• Drawbacks: someone must install, secure and maintain it. A system forgotten for five years is a risk, not a saving. It does not need a big server: a professional mini PC is plenty for an SME.

Telephony built into the collaboration suite. Microsoft Teams Phone or Zoom Phone: the phone becomes a feature of the tool your teams already use.

• For whom: companies already heavily invested in Microsoft 365 or Zoom, with teams mostly on PCs.
• Advantages: one app for everything.
• Drawbacks: licences that add up, greater dependence on a single US supplier, reception features sometimes limited.

There is also fixed-mobile convergence: your landline number rings directly on mobiles, with no desk phone. Handy for tradespeople, freelancers and sales staff.

The market players

The landscape moves fast: take this list as a map, not a ranking.

• Operators and SIP trunks: Proximus, Telenet Business and Orange Belgium, the big three; Dstny and Mixvoip among alternative operators.
• Phone systems and platforms: 3CX, widespread in SMEs, on site or hosted; FreePBX and Asterisk, the open source reference, free and powerful but requiring real know-how; Yeastar and Wildix, aimed at SMEs; Aircall, RingCentral, Zoom Phone and Teams Phone in the cloud.

The right choice depends less on the brand than on three questions: how many users, who provides support, and where your data goes.

Software to know

• The phone system (PBX): the brain. Queues, opening hours, voice menus, forwarding.
• Softphones: an app that turns a PC or smartphone into a phone. Each platform has its own; in open source, Linphone is a safe bet, MicroSIP is lightweight on Windows.
• Integrations: customer record shown on the call, click-to-call, calls logged automatically in the CRM or business software.
• Call recording: useful in disputes or for training, but the GDPR requires informing callers and justifying the purpose. You do not record everything by default.

Hardware: less than you think

SIP works with standard hardware from interchangeable brands.

• SIP desk phones: Yealink, Snom, Fanvil, Grandstream. A decent phone lasts ten years.
• DECT cordless phones: Gigaset, Yealink, Snom. For the workshop, warehouse or shop floor.
• Headsets: Jabra, EPOS, Poly. For those on the phone all day, the best investment on the list.
• Analogue adapters (ATA): a small box that connects an alarm, a fax or an old phone to a SIP line. Often the answer for "hidden" devices, to be checked with your alarm installer.
• The network: a PoE switch (the phone is powered through the network cable) and a router that can prioritise voice.

Many companies no longer have desk phones at all: a softphone on the PC, an app on the mobile, a good headset, done.

And where does AI come in?

Voice is exactly the kind of data AI can now handle. Telephony, a dull subject for twenty years, is becoming interesting again.

What already works:

• Call transcription and summaries. Every conversation becomes text, with a summary, sent to the CRM. 3CX, for example, offers call transcription, automatic summaries and sentiment analysis in its AI edition, with a choice of transcription engine, including a transcription server installed on your premises.
• Voicemail transcription. The message arrives by email as text: five seconds of reading instead of a minute of listening.
• Statistics. Recurring reasons for calls, peak hours, calls that go badly.

What is coming: the AI receptionist. An AI that answers the phone in natural language, in French, Dutch or English, at 3 a.m. as at noon: giving opening hours, booking an appointment, qualifying the request and transferring to the right colleague with a summary, taking a structured message. 3CX already offers an "AI Receptionist", and OpenAI's voice API accepts SIP calls directly: a standard SIP trunk can be connected to an AI agent without an exotic intermediary. Open telephony is telephony ready for AI; a copper line will never talk to anything.

For a medical practice, a restaurant or a tradesperson who misses calls because their hands are busy, every missed call is a customer calling the next competitor.

Safeguards:

• The AI Act requires transparency. Since 2 August 2026, Article 50 of the European AI regulation requires informing a person that they are interacting with an AI, unless it is obvious (systems already on the market have until 2 December 2026). Your virtual receptionist must therefore say so. See our article on the AI Act for SMEs.
• The GDPR applies to voices. A transcribed conversation is personal data: where is it processed, how long is it kept, who has access? These questions need a written answer.
• AI must not improvise. A voice agent must stick to what it knows (opening hours, published prices, calendar) and hand over to a human as soon as things go beyond that.
• Always a way out to a human, or at least a guaranteed callback.

Three ways to go about it

Example: a six-person estate agency

Illustrative case. An agency with two Proximus landlines, an alarm connected to the line, and six mobiles. The letter announces the end of copper in a year. The agency misses calls on Saturdays and during viewings.

What we would do: list what is connected to copper (the alarm, and an old fax nobody uses any more), port both numbers to a SIP trunk, hosted system or a small server, calls ringing on the desk phones then on the mobiles, voicemail transcribed by email. The alarm moves to a 4G transmitter with the installer. Later, an AI receptionist can take viewing requests on Saturdays, clearly announcing that it is an AI.

Where to start? Five questions

1. When is copper cut at our address, and which devices are still connected to it?
2. How many calls do we miss each week? If nobody knows, that is already an answer.
3. Who needs to be able to answer, and from where: office, home, site, mobile?
4. Where do we want our voice data stored: on site, in Europe, no preference?
5. What monthly budget, and who provides support the day it does not work?

With these five answers, the choice between cloud, on-site system or collaboration suite almost makes itself.

Test yourself

At ExsIT

Our own number, 02 733 04 59, runs on a SIP trunk, and we are working on an AI answering service designed for SMEs: simple, affordable, no expensive hardware.

The first contact is free: we listen to your needs, then propose an action plan. An inventory of what still depends on copper, choice of solution, number porting, network and security set-up and, if you wish, AI-assisted call handling.

For your IT person

• Network: voice priority (DSCP EF for RTP, CS3 for signalling), disable the router's SIP ALG, which often breaks calls behind NAT; plan RTP ports or an SBC.
• Security: SIP over TLS and SRTP where the operator allows, long unique extension passwords, geo-filtering and IP allow-list for the trunk, block unused premium-rate and international destinations, spending cap at the operator, fail2ban or equivalent.
• Codecs: G.711 A-law to the trunk in Europe, Opus between phones and softphones.
• Fax and alarms: T.38 if the fax must survive; for alarms, an IP or 4G transmitter rather than an ATA where the installer recommends it.
• Phone system: 3CX (PRO and AI editions), FreePBX on Asterisk, or Wazo; a virtual machine or mini PC is enough for a few dozen extensions.
• AI: check where transcriptions are processed (provider, region, retention) and record it in the GDPR register of processing activities.

Sources

3CX. (n.d.). A business phone system with built in AI features. https://www.3cx.com/pbx/ai-features/

Alcatel-Lucent Enterprise. (2023, November 23). New milestone achieved for Rainbow. https://www.al-enterprise.com/en/company/news/cspn-certification-rainbow-anssi

BIPT. (2023, June 20). Communication concernant la mise hors service du réseau de cuivre de Proximus. https://www.bipt.be/index.php/file/cc73d96153bbd5448a56f19d925d05b1379c7f21/71e9014801f4b72521e2882dde6d050c3d175e86/communication-mise-hors-service-reseau-cuivre-proximus-2023-06-20.pdf

Blog du Modérateur. (2026, July 29). IA Act : ce qui change le 2 août 2026. https://www.blogdumoderateur.com/ia-act-2-aout-2026/

Gourvennec, R. (2023, June 7). Ringover sécurise 20 millions pour investir notamment dans l'intelligence artificielle. Maddyness. https://www.maddyness.com/2023/06/07/ringover-levee-de-fonds/

Hajdari, U. (2026, June 30). Finland's last analogue landline phones go silent after 150 years. Euronews. https://www.euronews.com/next/2026/06/30/finlands-last-analogue-landline-phones-go-silent-after-150-years

mick2be. (2016, December 20). Wazo, le fork de XiVO, prend son envol. LinuxFr.org. https://linuxfr.org/news/wazo-le-fork-de-xivo-prend-son-envol

Mixvoip. (n.d.). Impressum. https://www.mixvoip.com/be/impressum

OpenAI. (n.d.). Realtime API with SIP. OpenAI Developers. https://developers.openai.com/api/docs/guides/realtime-sip

Proximus. (n.d.). Fin du réseau cuivre. https://www.proximus.be/fr/fibre/fin-du-reseau-cuivre

Solutions Numériques. (2022, February 24). Alliantel, Ipline et Openip (Groupe Destiny) deviennent Dstny. https://www.solutions-numeriques.com/?p=92633

Telavox. (2021, June 22). Telavox expands rapidly – acquires cloud solutions provider ALLOcloud in Belgium and France. Mynewsdesk. https://mynewsdesk.com/se/telavox/pressreleases/telavox-expands-rapidly-acquires-cloud-solutions-provider-allocloud-in-belgium-and-france-3111002

Wazo. (n.d.). Wazo Platform. https://wazo-platform.org