Belgium: SIP providers and connecting a number to the PBX

This page continues the general guide on connecting a provider's number to the PBX: that page covers what is the same for any operator — the two trunk modes, what to ask the provider, what to enter in the form, network requirements and the connectivity check. Here are the Belgian specifics: who in the country sells a number with a SIP trunk, what that operator issues and what of it to enter in Telephony → "Trunks and connections" → "Add provider".

The data was collected on 9 September 2026 from operator documentation and the regulator's materials (BIPT/IBPT); links are in the "Sources" section.

In short#

• You can buy a number with a SIP trunk in Belgium. A venue needs no licence and no permit: instead of a licence the country has a notification to the BIPT, and it is filed by the operator you buy connectivity from.
• The main feature of this market: the three largest operators do not offer a trunk over the public internet. Proximus delivers Business Trunking through its own session border controller and together with its own access line, Telenet through a managed gateway inside the customer's local network, and Orange Belgium only for sites inside its own IP VPN. Our PBX lives in the cloud and does not fit into their managed perimeter. So you need an operator that hands out a trunk over the public internet.
• If you have not picked an operator yet, take edpnet: it is the only one in the country that published the full set of parameters — server addresses, port, media port range and the G.711 A/µ codecs — and it works by IP, which matches the static address of a dedicated PBX exactly.
• If an address allowlist is inconvenient, take 3StarsNet or Voys België — both work in registration mode (REGISTER) with a login and a password, and Voys's preferred codecs (G711a, G722) match ours one to one.
• The main local pitfall is the royal decree on spoofing of 12 May 2024. Operators must block international calls presenting a Belgian number: since 01.09.2024 for geographic numbers and since 01.12.2024 for mobile ones. The decree does have an exception for cloud telephony, but it only applies with a written agreement listing the permitted numbers: you must warn the operator in writing about a PBX in someone else's cloud, not just "set up the trunk".
• The second pitfall is that a geographic number is firmly tied to an address inside its telephone zone. A zone number is issued against an address in that zone and can only be ported inside it. Without a Belgian address in the right zone, what is left is a number from an international provider — but then 100, 101 and 112 cannot be dialled through it.

Numbers in the country#

• The country code is +32. A fixed number is exactly 9 digits including the leading 0; a mobile number is 10 digits with the leading 0.
• Zones. Four conurbations have a single-digit zone code: 02 — Brussels, 03 — Antwerp, 04 — Liège, 09 — Ghent. All other zones have a two-digit code (010, 011, 014, 015, 016, 019, 050, 053, 056, 060, 065, 067, 071, 081, 085, 087, 089 and others). Hence two written forms: 0 + 1 zone digit + 7 subscriber digits (02 123 45 67) and 0 + 2 zone digits + 6 subscriber digits (071 12 34 56).
• Mobile numbers are 04xx + 6 digits (0475 12 34 56). Note that 04 is also the geographic zone of Liège; the two are told apart by the length of the number.
• Non-geographic and special numbers: 0800 — free for the caller, 070 and 078 — non-geographic with a charge, 0900/0903/0905/0906/0909 — premium information numbers, 1xx and 1xxx — short services (100 — ambulance and fire, 101 — police, 112 — the common European number).
• Dialling: inside the country always the full number with the zone code, even within your own zone (full dialling has been mandatory since 01.07.2000); abroad — 00 + country code.

On the "Lines" tab a number can be entered in any form: the PBX matches the last seven digits. ⚠️ For numbers in single-digit zones the subscriber part is exactly 7 digits, so numbers from different conurbations (02 123 45 67 and 03 123 45 67) are indistinguishable to the PBX. If the venue keeps numbers in several cities, check the routing of every line manually — "Add a number and routing".

Who issues a number with a SIP trunk#

The first five rows are operators whose mode and parameters are known in advance: their cards are below. The next seven issue trunk parameters only after a contract — they have a separate section. Why Telenet and Orange will not work is below.

edpnet#

A Belgian internet provider from Sint-Niklaas, in business since 1999, part of the Citymesh group. The only operator in the country that published its trunk parameters in full — down to the media port range and the choice of the incoming number format. Its authentication is by IP: "Based on IP address, no username/password needed".

What to enter in the admin panel

What to set up at the provider: give edpnet the static IP of your PBX — it is shown on the "Server" tab of the Telephony section; without it their platform will not recognise your calls → order the number of simultaneous calls (it is capped by the contract) → specify the numbers to be routed to the trunk → optionally switch the incoming number format from national to international with a plus.

Pitfalls ⚠️ By default the incoming number arrives national with a leading zero (032656700) rather than as +32…: matching a line by the last seven digits survives this, but the numbers will look unusual in the list of lines. The media ports on the operator's side are 19000–27192/UDP: if the venue filters outgoing traffic, that range has to be allowed. The codec list also includes G.729, which we do not have, but G.711 A-law and G.711 µ-law come first, so negotiation should fall back to them. And one more thing: as of 09.09.2026 the brand has moved into the Citymesh group, so when ordering check who sells the trunk now, whether these addresses are still in force and whether the trunk is sold without their own access line. Source: Configuration: SIP trunk, How do I create an edpnet trunk in 3CX — 09.09.2026.

3StarsNet (Sewan Belgium)#

A Belgian operator that joined the Sewan group (its support portal opens under that brand). The only local operator whose registration addresses are published openly — that is, the trunk can be set up without an exchange of letters about an address allowlist.

What to enter in the admin panel

What to set up at the provider: order a SIP trunk and the number of channels → route the purchased numbers to the trunk → clarify in what form the number arrives on an incoming call and which numbers may be presented on outbound calls.

Pitfalls ⚠️ There are three platforms, by contract generation: sip. is the first, voip. the second, v3. the third; only the operator's support knows which one is yours. The operator asks to keep the registration interval short — between 60 and 120 seconds — so on packet loss the trunk "blinks" more often than usual. And most importantly: the article with the parameters was last updated around 2018 — confirm the addresses and the port with support in writing before connecting. Source: Sip settings for 3Starsnet — 09.09.2026.

Voys België#

The Belgian arm of the Dutch operator Voys with an office in Antwerp, running on the VoIPGRID platform. The product is called "SIP-trunk voor jouw telefoniecentrale" and is aimed exactly at a third-party PBX: the description names Asterisk-compatible systems directly. The platform's preferred codecs are G711a and G722, so our whole set goes through.

What to enter in the admin panel

What to set up at the provider: create a VoIP trunk in the account → take the Account ID and the password → attach the purchased Belgian numbers to the trunk → choose the incoming number format (by default the platform delivers the full number with a plus) and the format of your own number on outbound calls.

Pitfalls ⚠️ Port 6060 on new trunks is the most frequent cause of "not registering". The login is the Account ID, not a number: routing by "Lines" works because the incoming call carries +32…. The platform reads your outbound number from the Remote-Party-ID header, and our PBX does not send it — the "Present as" rule will not work and the call will go out with the trunk's default number; the only workaround is to make the needed number the trunk's default number in the account. The platform asks to leave the STUN and Outbound Proxy fields empty. If you filter traffic by address, ask the operator for the current networks of the Belgian platform specifically. Source: voys.be/voip-trunk, Algemene trunkdetails — 09.09.2026.

Mixvoip#

A Luxembourg operator with a Belgian office in Braine-l'Alleud, more than 17 years in SIP trunking and regulatory coverage in over 20 countries. It sells Belgian and Luxembourgish numbers and states Asterisk support openly — "Mixvoip's experienced engineers are well-versed in Asterisk".

What to enter in the admin panel

What to set up at the provider: order the SIP trunk itself rather than their cloud PBX → pick Belgian numbers → ask them to enable the G.711 A-law codec → clarify how tone dialling (DTMF) is transmitted.

Pitfalls ⚠️ According to the interoperability report the platform offers only G.711A — no G.722 and nothing else; that is enough for voice, but a fax over such a trunk is possible only as ordinary audio, T.38 does not work. Packages with unlimited minutes are given only to systems from the operator's own certified list and through a partner — our PBX has no such status, so billing will be per minute. The parameters themselves come from a 2021 interoperability report: ask the operator to confirm them before ordering. On the plus side: according to the same report the operator lets a third-party number through on outbound calls — a rarity for Belgium, but worth confirming in writing. Source: SIP Trunk — Bring Your Own Phone System, Integrate Asterisk with Mixvoip SIP Trunks — 09.09.2026.

Proximus#

The incumbent and the largest operator in the country (formerly Belgacom). It sells businesses Business Trunking — connecting a corporate phone system to its network; the product is available only through sales or a partner, with a contract and a range of numbers assigned to a specific PBX. The parameters come from the public 82-page connection specification, a primary source.

What to enter in the admin panel

What to set up at the provider: give Proximus the static IP of your PBX from the "Server" tab — their controller identifies the system by a one-to-one address mapping → obtain the system identifier (pbxPUID) and the range of numbers → check that the range covers every number the venue intends to present on outbound calls.

Pitfalls ⚠️ By design Business Trunking is sold together with a Proximus access line to the customer's site, while our PBX sits in the cloud: ask sales directly whether their controller will let calls in from a cloud server address and on what terms — that is the first question, not the last. The transport is strictly UDP: "let's try TCP" breaks compatibility with their own specification here. The outbound number is checked against your range, and one that fails the check is silently replaced with the default number. Calls with a withheld number, forwarding to an external number and blind transfer are billed to the company's main number. A rejection by the load control arrives as 403 Forbidden. Source: Proximus — Business Trunking connection specification v2.2 — 09.09.2026.

Operators that issue parameters under contract#

For these operators a trunk for a third-party PBX is a regular product, but the server address, the mode and the credentials appear only in the contract or in the customer portal. The list of questions worth asking the account manager before signing is in "What to ask the provider". Be sure to ask two of them: do they hand out the trunk over UDP or TCP (our PBX does not support encrypted signalling at all) and is the G.711 A-law codec allowed.

• Dstny Belgium (formerly Destiny) — the largest Belgian cloud telephony operator, founded in Belgium and now part of a European group. A trunk to the outside is a partner scenario: their main product is their own. What is known: encrypted signalling is not offered, the main trunk number is set in E.164 format, and only the numbers of your own account may be presented on outbound calls.
• TeleVoIP — an operator from Ninove: cloud and hosted telephony, SIP trunking, call centre solutions. According to compatibility matrices it is the only Belgian operator that declares both encrypted signalling support and the ability to present a third-party number on outbound calls. The first question for their support: do they hand out a trunk over plain UDP.
• Belcenter — a business operator from Braine-l'Alleud with its own network, 23 years on the market; its "IP telephony (SIP Trunk)" product is positioned directly for the customer's own system. The key fact for us is confirmed: "Native support for G711 (without compression) and G722 codecs" — both of these codecs are ours. The network is redundant with two sites in Belgium and three in Europe, and numbers are available in 50 countries. The wording "without going through the Cloud" hints that their typical scenario is a system on the customer's premises: ask about a PBX in the cloud explicitly.
• Teamtel — an operator from Hasselt, 15 years on the market, describing itself as the SIP provider for over 1200 Belgian small and medium companies; the trunk is claimed to be compatible with any telephone system. There are no technical parameters or a price list on the site — only on request.
• IP Nexia — a Brussels provider combining the roles of operator and integrator; the "VoIP trunk" product for a customer's system exists, but the parameters are not published. They are used to installing and configuring the system themselves, so spell out the "the system is not yours, please give me the parameters" scenario separately.
• UC Experts — a distributor from Aalter and a top-tier partner of major PBX vendors; it has no public SIP parameters of its own, the trunk is handed out through a platform template. The main trunk number is set in E.164 and a third-party number may not be presented.
• Tech IT — an operator and integrator from Luxembourg that also works in Belgium. There are no public parameters; from its compatibility profile it is known that encrypted signalling is not offered and the main trunk number is set in E.164.

Who will not work#

• Telenet Business. The second largest operator in the country. Its "SIP-trunking" product is sold for the customer's own system too, but it is delivered by a managed gateway inside your local network: authentication goes to the private address of that gateway, and only the operator's staff have access to it. Such an address is unreachable from the cloud, and in compatibility matrices the Telenet profile is marked as no longer supported. The scenario is possible only if the venue has its own link or VPN to the site with the gateway.
• Orange Belgium. The third large operator (it absorbed VOO in 2023). Its "VoIP Trunking" is "a voice service for all your sites connected via Orange IP VPN", that is a service inside their own network. The phrase "international SIP trunks" in the description of their cloud telephony refers to connecting foreign sites to their PBX, not to yours. There is one realistic option: the venue already has an Orange IP VPN connection and our PBX ends up inside that perimeter — this has to be discussed with the operator separately.
• Proximus formally does not belong on this list — technically it is compatible (UDP, G.711a, authentication by IP) — but it is sold together with its own access line, so until sales answer, treat it as an option "in question" rather than a working one.

International providers with Belgian numbers#

Belgian numbers are sold by Bandwidth, Telnyx, Twilio, DIDWW, Plivo, Vonage, CM.com, Telxi, Zadarma, Sonetel and others. This is the default route if the company is registered outside Belgium or if numbers in several countries are needed at once.

• Belgium is Bandwidth's "home" market. Voxbone, whose numbers are now sold under the Bandwidth brand, was founded in Brussels; Belgian landline numbers are one of its historical products. Its mode is authentication by IP, which fits the static address of a dedicated PBX.
• A landline number will require a local address here too. The tie is to the subscriber's address in a specific telephone zone, and international providers formalise it as proof of address or business registration. The exact form of the requirements differs — check before paying for the number.
• Emergency calls through an international number do not work by default: 112, 100 and 101 cannot be dialled unless the provider has sold a separate emergency calling service with an address attached. The venue must be aware of this and keep a backup way to call for help.
• The spoofing decree affects them more than local operators. A call with a Belgian number sent from abroad arrives in the Belgian network exactly as an international one — and falls under mandatory blocking. Ask the provider in advance how it secures the exception for cloud telephony.
• The modes differ. Cards for Zadarma, Telnyx and Twilio are already in the catalogue when adding a provider — the server address and the mode will be filled in automatically.

Number porting#

• Both fixed and mobile numbers can be ported; the mechanism has been supervised by the BIPT since 2006. The request is filed by the new operator — the one you are moving to — on a written mandate from the subscriber; the technical part of the port must fit into one working day after the request is confirmed.
• A fixed number can only be ported inside its own telephone zone. The regulator's wording is direct: you keep your fixed number if you stay in the same telephone area. Moving the venue to another zone means changing the number; there is no lawful way to take a landline number outside its zone.
• A mobile number is ported without geographic restrictions.
• A geographic number is issued against an address in its own zone: getting, say, a Liège 04… without an address in one of that zone's municipalities will not work. For a chain of venues in different cities this means different numbers rather than one "nice" number for all.
• Emergency calls during a port. The obligation to provide 112, 100 and 101 passes to the new operator, and the address attached to the number must be kept up to date: the emergency services use it to determine the location of the call.

Rules and documents#

If it does not work#

1. edpnet has neither incoming nor outgoing calls, yet the address and the port are correct. Most likely your address is not on the allowlist: this operator identifies the system by IP only. Take the static address from the "Server" tab and send it to their support. The same applies to Proximus.
2. Incoming calls arrive but no line is selected. Check the number format: edpnet sends national with a leading zero by default (032656700), Proximus sends +32…, and with Dstny, UC Experts and Tech IT the main trunk number is set in E.164. The second case is a collision of the last seven digits between numbers from different conurbations (02 123 45 67 and 03 123 45 67): separate such lines manually.
3. The trunk to Proximus does not come up. Check the transport: their specification allows UDP only and explicitly forbids the system to fall back to TCP. Also check that the address you gave the operator is the one the system actually sends calls from: a mismatch is answered with 403 Forbidden.
4. The wrong number is presented on outbound calls. With Proximus a number outside your range is silently replaced with the default one. With Voys the platform reads the number from the Remote-Party-ID header, which our PBX does not send. With most Belgian operators presenting a third-party number is not possible at all — the only workaround is to make the needed number the trunk's default number in the operator's account.
5. The call connects but there is silence. The codecs did not negotiate. Mixvoip offers a single codec, G.711A; edpnet's list also includes G.729, which we do not have. Ask the operator to enable G.711 A-law or G.722 — requirements for the provider.
6. The 3StarsNet trunk "blinks". The operator asks for a short registration interval — 60 to 120 seconds — so re-registrations become noticeable on packet loss. The second reason is the wrong platform: it has three addresses (sip., voip., v3.), and support knows which one is yours.
7. Calls were coming through and then suddenly stopped arriving from abroad. This may be blocking under the spoofing decree: a Belgian number on an international call is blocked by default. What is needed is a written agreement with the operator listing the permitted numbers and recording that the system runs in the cloud.
8. "Check connectivity" is silent and the trunk is from Telenet or Orange. There is nothing to check here: the Telenet trunk lives in your local network behind a managed gateway, and the Orange one inside their IP VPN. Neither address is reachable from the cloud.

Causes that do not depend on the country are in "If calls do not go through". Checking the address and the port — "Check connectivity".

Frequently asked questions#

Which operator should I choose if nothing is connected yet?#

edpnet. It is the only one in the country that published the full set of trunk parameters, it works with authentication by IP — which matches the static address of a dedicated PBX exactly — and its first codecs are the same as ours. The fallbacks, if an address allowlist is inconvenient, are 3StarsNet and Voys België: both work with a login and a password.

Can I get a Belgian number if the company is registered outside Belgium?#

A landline number is hard: it is issued against the subscriber's address in a specific telephone zone, and the operator verifies that tie. Belgian operators do not describe a public procedure for foreign companies. The practical route is to buy a Belgian number from an international provider: it will ask for documents too, but its procedure for foreign legal entities is documented. Keep in mind that 112, 100 and 101 do not work through such a number.

Why will Proximus, Telenet and Orange not work?#

With Telenet the trunk is delivered by a managed gateway inside your local network, and with Orange only inside their corporate IP VPN; a PBX in the cloud fits neither perimeter. Proximus is technically compatible, but it sells Business Trunking together with its own access line to the customer's site: whether their session border controller will let calls in from a cloud server address has to be asked of sales before signing the contract.

What is the royal decree on spoofing and does it concern me?#

The decree of 12 May 2024 obliges operators to block international calls presenting a Belgian number: geographic ones since 01.09.2024 and mobile ones since 01.12.2024. Your PBX is physically located abroad, so the question is directly yours. The decree does contain an exception for cloud telephony, but it applies only with a written agreement with the operator listing the permitted numbers and recording that the subscriber can be identified within 24 hours at the regulator's request. Warn the operator in writing before connecting.

Can I attach numbers from different Belgian cities to one PBX?#

You can, but carefully. The PBX matches a line by the last seven digits, and for numbers in the 02, 03, 04 and 09 zones the subscriber part is exactly seven digits: 02 123 45 67 and 03 123 45 67 are indistinguishable to it. For numbers in two-digit zones (071, 081 and the like) one digit of the zone code also falls into the tail, so the risk there is lower. When adding numbers from different conurbations, check the routing of every line with a test call.

How many channels (simultaneous calls) does a venue need?#

Usually 2–3: one is busy with a guest, the second with a courier or a supplier. With edpnet and 3StarsNet the number of simultaneous calls is set by the contract, with Voys lines are ordered one by one in the account. Ask about this before signing: "it stops ringing after the second call" is almost always a contract limit rather than a fault.

Sources#

All links checked on 09.09.2026.

Operators

• edpnet — Configuration: SIP trunk: https://support.edpnet.be/hc/en-us/articles/17218482454930-Configuration-SIP-trunk
• edpnet — How do I create an edpnet trunk in 3CX: https://support.edpnet.be/hc/en-us/articles/18505377830162-How-do-I-create-an-edpnet-trunk-in-3CX
• 3StarsNet — Sip settings for 3Starsnet: https://3starsnet.zendesk.com/hc/en-us/articles/360001476394-Sip-settings-for-3Starsnet
• Voys België — SIP-trunk voor jouw telefoniecentrale: https://www.voys.be/voip-trunk/
• Voys — general trunk parameters (platform wiki): https://wiki.voys.nl/index.php/Algemene_trunkdetails
• Mixvoip — SIP Trunk, Bring Your Own Phone System: https://www.mixvoip.com/sip-trunk/
• Mixvoip — Integrate Asterisk with Mixvoip SIP Trunks: https://www.mixvoip.com/insights/asterisk/
• Proximus — Business Trunking connection specification v2.2: https://www.proximus-cdn.com/dam/jcr:6746d62c-c9ef-4243-80b4-df64998c2c10/PXM_IMS_Corporate_VoIP_UNI_specification_SIP_signalling_Business_Trunking_with_IMS_services_v2.2.docx
• Belcenter — IP telephony (SIP Trunk): https://www.belcenter.be/en/solutions/ip-phone-sip-trunk/
• Teamtel — SIP trunk: https://teamtel.be/en/diensten/sip-trunk/
• IP Nexia — VoIP trunk: https://www.ipnexia.com/ip-telephony-solutions/voip-trunk/
• Telenet Business — Bellen via internet met SIP-trunking: https://www2.telenet.be/business/nl/sme-le/telefonie/vaste-telefonie/bellen-via-internet-sip-trunking.html
• Orange Belgium — VoIP Trunking: https://business.orange.be/en/networks/voip-trunking
• Orange Belgium — Cloud Telephony: https://business.orange.be/en/cloud-telephony

Regulator and law

• BIPT — Notifying the BIPT: https://www.bipt.be/operators/notifying-the-bipt
• IBPT — obtaining and managing numbers: https://www.ibpt.be/operateurs/obtenir-et-gerer-des-numeros
• BIPT — royal decree on spoofing: https://www.bipt.be/operators/spoofing-royal-decree
• Royal decree of 12 May 2024 (text): https://etaamb.openjustice.be/fr/arrete-royal-du-12-mai-2024_n2024005253.html
• BIPT — number portability: https://www.bipt.be/consumers/number-and-e-mail-portability
• IBPT — geographic and non-geographic numbers: operational aspects: https://www.ibpt.be/operateurs/publication/numeros-geographiques-et-non-geographiques-banque-de-donnees-et-aspects-operationnels

Related pages#

• Connecting a provider's number to the PBX — the common steps, trunk modes, network, connectivity check.
• Setting up SIP phones — how to connect desk phones and DECT handsets to extensions.