Spain: 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 everything that is the same for any operator — the two trunk modes, what to ask the provider, what to fill in the form, network requirements and how to test the connection. Here is the Spanish specifics: who sells a number with a SIP trunk in the country, what that operator issues and what of it goes into Telephony → "Trunks and connections" → "Add provider".

The data was collected on 9 September 2026 from operator documentation and regulator materials (CNMC, BOE); the links are in the "Sources" section.

In brief#

• You can buy a number with a SIP trunk in Spain, and your business needs neither a licence nor a registration for it. The service is sold by an operator listed in the CNMC Registro de Operadores; you are simply its subscriber.
• The market is crowded, but almost everyone hides the parameters behind the customer portal. Out of the sixteen Spanish operators we checked, the server address, port and codecs are published by two: netelip and GoTrunk. The rest — from VOZ.COM to Movistar — send the parameters by email only after you sign up.
• If no operator has been chosen yet, take netelip, product "Línea SIP", in registration (REGISTER) mode: it has an open knowledge base, the same operator sells you the number, and the trunk form is filled in without calling a sales manager. If you need a number right now — GoTrunk: a Spanish number for €4 a month with instant activation and a ready-made Asterisk guide.
• The main local pitfall is that calls without a calling number are blocked by law. Since 07.03.2025 a Spanish operator is obliged to block calls with an empty calling number (Orden TDF/149/2025, art. 4), while at netelip outgoing calls are hidden (oculto) by default. So the “Show as” field with a real number from your contract is not cosmetics but a condition for the trunk to work.
• The second pitfall is dead brands in search results. Since 2017 Vozelia is Sewan, Masvoz and Telsome are Enreach, VozTelecom is Gamma (gammacom.es), LCRcom is Aire. The old sip.vozelia.com host today points at Microsoft infrastructure: a configuration found on Google will not work.
• Documents. The contract is signed with a Spanish entity (NIF/CIF); none of the operators we checked describes a public procedure for a foreign company. In that case it is easier to take a +34 number from an international provider.

Numbers in the country#

• The country code is +34. The plan is closed, 9 digits: all nine digits are always dialled, wherever you call from. There is no leading zero in Spanish numbering.
• Landline (geographic) numbers start with 9 or 8 and contain a province prefix: two digits for the large zones (91 Madrid, 93 Barcelona, 96 Valencia) and three for the rest (950 Almería, 981 A Coruña). Together with the subscriber part it is the same 9 digits: 911 82 94 84.
• Mobile numbers are also 9 digits and start with 6 or 7.
• Free for the caller — 800 and 900; 901 and 902 are shared-cost or premium and are going out of practice (see "Rules and documents"); 905, 906 and 80X are premium.
• The emergency number is 112, the pan-European one.

In the "Lines" tab the number can be entered in any format: the PBX matches the last seven digits. ⚠️ In Spain seven digits are fewer than the full number, so numbers from different provinces can share the same tail (950 12 34 56 and 981 12 34 56 both end in 0123456). Numbers from the same province are distinguished fine; with numbers from different provinces check the routing of each line manually — "Adding a number and routing".

Who issues a number with a SIP trunk#

The first two rows are the operators whose trunk parameters are in public documentation: their cards are below. The other local ones hand out the server address, login and password only after a request or a contract — they have a separate section.

netelip#

An operator from Málaga working in Spain and Latin America, the only one on the market with an open knowledge base of parameters. It has two products, and they work differently:

• "Línea SIP" — a SIP account: the service itself is free, you pay for the number (from €1.95/month) and for outgoing calls. Authentication is always by registration, the login and password are in the portal under "Configurador de Dispositivos", up to 30 simultaneous calls per account. This is the simplest path: our trunk form is filled in completely.
• "SIP Trunking" — a "grown-up" trunk with IP authentication. In the portal (⚙️ → SIP Trunking) the "Numeración de acceso" section enables the numbers and sets the destination IP for incoming calls, while "Terminación de llamadas" holds the calling identifier, the IP and port of your PBX and the number of channels.

What to enter in the admin panel (REGISTER mode, the "Línea SIP" product)

In the "SIP Trunking" product it is the same host and port, but with the "IP auth (no registration)" checkbox, an empty login and password; our side needs a static address — the dedicated PBX has one on the "Server" tab.

What to set up at the provider: buy a number → in "Numeración de acceso" put the public IP of your PBX as the destination for incoming calls → in "Terminación de llamadas" set the calling identifier (otherwise outgoing calls leave hidden and get blocked), your source IP and port and the number of channels → for "Línea SIP" take the login and password from "Configurador de Dispositivos" and set "plan de marcado: España" → insist on G.711 a-law/u-law.

Pitfalls ⚠️ The operator's default codec is G.729, which our PBX does not speak: the call connects but there is no audio. The account allows G711a, G711u, G722, GSM, iLBC and G723 — the first three, the ones we need, are enabled in the account settings. Authentication in "SIP Trunking" checks both the IP and the port: traffic from a different port is rejected by the operator (the reply shows rport). On a prepaid account simultaneous calls share the balance — when it runs low the system cuts the call with a voice announcement, which from the outside looks like random drops. The operator also asks you to disable SIP ALG on the router, but that does not apply to a dedicated PBX in the cloud.

Source: SIP Trunking — preguntas frecuentes, Línea SIP — configuración del servicio — 09.09.2026.

GoTrunk#

The Spanish front of the international Level 7 Systems platform (gotrunk.es, technical zone ssl7.net) — the only one in this list with ready-made Asterisk configurations, both for sip.conf and for PJSIP. A Spanish number costs €4 to set up and €4 a month, includes 2 channels, is activated instantly, and porting a number in is free.

What to enter in the admin panel

What to set up at the provider: buy a Spanish number → choose the mode (put the public IP of your PBX from the "Server" tab on the allowlist, or take a login/password pair) → point the number at the trunk → buy extra channels beyond the two if needed.

Pitfalls ⚠️ The operator has two credential pairs — inbound and outbound; our form has a single one, so use the inbound pair for registration, and if outgoing calls are rejected, ask support which pair they expect on outbound. The platform codecs are ALAW, ULAW, G.722 and G.729, so our whole set passes (the operator recommends G.711 u-law). The provider is international: before going live, ask in writing whether it terminates your outgoing calls to Spanish subscribers inside Spain — whether the calls arrive at all depends on that (see "International providers" below).

Source: IP PBX Configuration — Asterisk, Asterisk PJSIP v18, Numeración — 09.09.2026.

Contract-only providers#

These operators do have a SIP trunk, but they do not publish the server address, the port or the mode — everything is issued after a request or a contract. There can be no "what to enter" table here: ask the manager for the parameters using the list from "What to ask the provider" and enter them into the same form as for the others. When ordering, state three things straight away — the PBX is in the cloud with a static IP, not behind your router; you need G.711 a-law/u-law, not G.729; you need UDP or TCP without TLS and SRTP. These three points weed out incompatible operators before you sign up.

• VOZ.COM — a large operator (Barcelona, Madrid) strong in call centres. From €9 a month, including 10 channels (extended for free) and a landline number in any province or a 902; activation and cancellation are free. Authentication is double: a login with a password and a fixed public IP — the ideal mode for our dedicated PBX. There is a safety net: if the registration is lost, incoming calls are diverted to ordinary lines or mobiles — convenient, but it means "silence on the trunk" can be masked by that diversion. The 902 they give away should not be put on the venue's public page (see "Rules and documents").
• Sewan Comunicaciones (ex-Vozelia) — a certified 3CX provider selling through distributors; the parameters come from the Sophia panel. In the 3CX template SRTP is disabled by a separate option — we do not have it at all, so it must be disabled. The trunk's main number is entered in E.164, and in the operator's known configurations the codec is G.729: insist on G.711 when the trunk is created.
• Enreach España (ex-Masvoz, ex-Telsome) — the product is called exactly "SIP Trunk — conecta tu Centralita IP", with as many channels and numbers as you need and a fallback diversion to a backup number if the internet fails. It is primarily a cloud PBX company, and the salesperson will offer that by default — ask specifically for the outbound trunk.
• Gamma España (ex-VozTelecom) — the trunk is called "Direct" (Básico / 4 / 8 / 8 Plus / Unlimited), and Asterisk is listed in their "Centralitas Homologadas" section. It is sold through distributors and usually together with their own access and router, so connecting a cloud PBX has to be agreed separately. Capacity is counted in channels in advance.
• Citelia — an operator from Málaga, a certified 3CX provider. Two things are known for certain from its guide: the trunk's main number is entered in the national format (911829484), and outgoing calls may present only numbers from your own account. So every DID of the venue must be attached to the account.
• VADAVO — an operator from Málaga with a cheap entry point: a trunk from €2 a month + VAT, engineers who help with the setup and a support portal. Their examples are written for 3CX and Yeastar — ask for the Asterisk parameters separately.
• Sarenet — a Basque operator and ISP (Bilbao) with a long-standing voice platform, a business trunk in registration mode. Ask the operator for the current server address and at the same time ask them to allow your PBX IP: the operator must send calls from the same address you register to.
• OHZ, masIP, Adiptel, Duocom, Zerovoz, Telxi — small operators and resellers who make a point of not publishing parameters: "we configure the trunk and hand you the SIP parameters ready for your PBX within 24–48 hours". They claim compatibility with Asterisk, FreePBX, 3CX, Issabel, Cisco, Avaya and Yeastar.
• Aire (ex-LCRcom) — a wholesale operator selling through partners; for a single venue this path is longer than netelip or GoTrunk.
• Movistar, Vodafone España, Orange España — at all three the corporate "SIP" voice service is sold together with their access and equipment, and none of them publishes a guide for connecting a third-party Asterisk. The practical route for a venue is not to fight the big three but to port the number to an alternative operator.
• Fonvirtual — a cloud PBX and numbers (including 900 and international ones), but it has no section about a trunk to a third-party PBX: the /troncal-sip/ and /sip-trunk/ pages do not open. You can buy a number there, but bringing it into our PBX is only possible by porting it to an operator that has a trunk.

International providers with Spanish numbers#

Spanish numbers are sold by DIDWW, Telnyx, Twilio, Plivo, Vonage, Bandwidth, Sinch, Infobip, Sonetel and Zadarma. This is the default route if your company is not registered in Spain: local operators sign the contract with a Spanish entity, while international ones accept an address in the client's country of registration wherever the regulator does not require a local one.

• Documents will still be asked for. For a +34 landline they usually ask for proof of address and business registration; the exact set depends on the number type and is shown in the provider's portal when ordering.
• The modes differ. Telnyx and DIDWW offer both registration and a static IP endpoint; Twilio Elastic SIP Trunking works by IP only — you will need the static address of your PBX; Zadarma uses registration and has a ready-made Asterisk guide. The Zadarma, Telnyx and Twilio cards are already in the catalogue when adding a provider: the server address and mode are filled in for you.
• ⚠️ A Spanish trap that does not exist in other countries. The operator is obliged to block incoming calls from abroad if the calling number is a Spanish one (Orden TDF/149/2025, art. 5). As long as the call leaves from a Spanish operator, everything is fine. But the "Spanish number at an international provider + calls to Spaniards from that number" scheme works only as long as the provider terminates such traffic inside Spain. Ask the provider about this in writing before going live.

Number porting#

• Porting in Spain is a standard and fast procedure: both fixed and mobile numbers can be moved, the process is initiated by the receiving operator (the one you are moving to), and the deadlines are regulated by the CNMC. At alternative operators porting is usually free: GoTrunk ports a number in for free, and netelip and VOZ.COM have dedicated "Portabilidad" sections. Check the exact number of working days with the operator when you file the request.
• The number's owner must match. The contract and the porting run in the owner's name (NIF/CIF); an owner change is done before the port — otherwise the request is rejected, which is the classic reason for a refusal.
• A geographic number is tied to its province. If the venue moves, the number stays, but many operators issue a "landline number of another province" only against an address there — check in advance.
• 902 and 901 are usually not worth carrying into the new setup: their role in customer service is effectively over, and it is more useful to move the venue's public number to 800/900 or to a geographic number.
• Emergency calls. 112 must work from any trunk; test it separately after connecting. At most operators the call is routed by the contract address rather than by the actual location — tell the operator the venue's real address.

Rules and documents#

If it does not work#

1. Outgoing calls do not reach the subscriber or are rejected while the trunk is registered. Almost certainly the call leaves without a number: at netelip a hidden number is the default state, and a Spanish operator is obliged to block such calls. Set the number in the provider's portal ("Identificador de llamada", or "Terminación de llamadas" for a trunk) and in the outbound rule in the “Show as” field.
2. The call connects but there is silence in one or both directions. The operator negotiated only G.729 — our PBX speaks G.711 a-law/u-law and G.722. This happens at netelip (it is its default codec) and in old Sewan configurations: ask support to enable G.711 on your account.
3. netelip "SIP Trunking": calls are rejected although the IP is correct. The operator checks not only the address but also the source port: traffic must leave from an allowed port. Check with the operator which port is set in "Terminación de llamadas".
4. A guide found online does not work at all. Check the brand name: Vozelia → Sewan, Masvoz and Telsome → Enreach, VozTelecom → Gamma (gammacom.es), LCRcom → Aire. The old hosts of these brands are dead — sip.vozelia.com today points at Microsoft infrastructure.
5. Calls to two numbers land on the same line. The last seven digits of Spanish numbers do not contain the whole province prefix, so numbers from different provinces may share a tail. Separate such lines manually or take numbers from the same province.
6. A Spanish number at an international provider does not reach Spanish subscribers. This is art. 5 of the order: a call with a Spanish calling number that arrives in Spain over an international interconnect must be blocked by the operator. Ask the provider where your outgoing calls are terminated.
7. The operator demands TLS on port 5061 or SRTP. This is not supported for trunks — ask for an ordinary UDP or TCP account (most operators have one) or choose another operator.

Causes that do not depend on the country are in "If calls do not go through"; the SIP trace in the trunk menu is described there too. Checking the address and port — "Test the connection". Network and codec requirements — "Network and compatibility".

FAQ#

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

netelip, the "Línea SIP" product: its host, port and codecs are published, the mode is registration, and the same operator issues the number. If you need a number today — GoTrunk: €4 a month, two channels included, instant activation and a ready-made Asterisk guide. Both can be connected without ever calling a sales manager.

Can I get a Spanish number if my company is not registered in Spain?#

At a local operator — hardly: the contract is signed with a Spanish entity (NIF/CIF), and none of the operators we checked describes a public procedure for foreign companies. The practical route is an international provider with +34 numbers (DIDWW, Telnyx, Twilio, Zadarma); it will ask for documents for a landline number too, but it accepts an address in the company's country of registration.

Why do outgoing calls leave with a hidden number, and what does that cause?#

At netelip a hidden number is the default state and has to be turned off in the portal. What it causes is blocking: since 07.03.2025 a Spanish operator is obliged to cut calls with an empty calling number. In other words, "anonymous" outgoing calls in Spain simply do not reach the subscriber.

Will a SIP trunk from Movistar, Vodafone or Orange work?#

Probably not. At the big three the voice service is sold together with their access and their router, while our PBX lives in the cloud with its own static address. None of the three publishes a guide for connecting a third-party Asterisk. If the number is already with them, port it to an alternative operator.

Is the free 902 number worth taking?#

Not for customer service: a call to a support line may not cost more than an ordinary call to a landline or mobile number, and 902 has effectively been retired from that role. For the venue's public number take a geographic number or 800/900 — the latter are explicitly allowed as a calling number on outgoing calls.

How many channels does a venue need?#

A channel is one simultaneous conversation. A restaurant usually needs 2–3: one is taken by a call to a guest, the second by a courier or a supplier. A netelip "Línea SIP" account allows up to 30 simultaneous calls, GoTrunk includes two channels in the price of the number, and VOZ.COM has ten in the base plan. Confirm the number of channels before signing.

Sources#

All links checked on 09.09.2026.

Operators

• netelip — SIP Trunking, preguntas frecuentes (hosts, port, incoming number format): https://www.netelip.com/centro-de-ayuda/sip-trunking/preguntas-frecuentes/
• netelip — SIP Trunking, configuración del servicio: https://www.netelip.com/centro-de-ayuda/sip-trunking/configuracion-del-servicio/
• netelip — Línea SIP, configuración del servicio (authentication by registration): https://www.netelip.com/centro-de-ayuda/linea-sip/configuracion-del-servicio/
• netelip — Soluciones técnicas Línea SIP (codecs, SIP ALG, NAT): https://www.netelip.com/centro-de-ayuda/linea-sip/preguntas-frecuentes/soluciones-tecnicas-linea-sip/
• GoTrunk — IP PBX Configuration: Asterisk: https://gotrunk.com/docs/ippbxconfiguration/asterisk/
• GoTrunk — IP PBX Configuration: Asterisk PJSIP v18: https://gotrunk.com/docs/ippbxconfiguration/asteriskpjsipv18/
• GoTrunk — Network configuration (addresses, ports): https://gotrunk.com/docs/networkconfiguration/
• GoTrunk (ES) — Numeración and Spanish number pricing: https://gotrunk.es/numeros/eur/
• VOZ.COM — Trunk SIP: https://voz.com/trunk-sip/
• Vozelia — "Ahora Vozelia es Sewan": https://www.vozelia.com/
• Enreach España — SIP Trunk: https://enreach.es/sip-trunk/
• Gamma España — Direct (trunk SIP) and supported PBXs: https://www.gammacom.es/trunksip-siptrunk-distribucion-oigaa-direct/
• Citelia — trunk configuration guide (on the 3CX site): https://www.3cx.es/foro/threads/citelia-gu%C3%ADa-de-configuraci%C3%B3n-de-la-troncal-sip-espa%C3%B1a.112132/
• VADAVO — SIP Trunk: https://www.vadavo.com/sip-trunk/
• OHZ — SIP Trunk para empresas: https://ohz.es/sip-trunk-para-empresas/
• 3CX — list of supported SIP trunks in Spain: https://www.3cx.com/partners/sip-trunks/espana/

Regulator and law

• Ley 11/2022, de 28 de junio, General de Telecomunicaciones: https://www.boe.es/buscar/doc.php?id=BOE-A-2022-10757
• Orden TDF/149/2025, de 12 de febrero (consolidated text): https://www.boe.es/buscar/act.php?id=BOE-A-2025-2870
• CNMC — Registro de operadores de redes y servicios de comunicaciones electrónicas: https://www.cnmc.es/sectores-que-regulamos/telecomunicaciones/registro-de-operadores
• Plan Nacional de Numeración Telefónica: https://digital.gob.es/telecomunicaciones-infraestructuras-digitales/servicios/numeracion/plan

Related pages#

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