Greece: 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 one covers everything that is the same for any carrier — the two trunk modes, what to ask the provider, what to type into the form, network requirements and the connection test. Here is the Greek specifics: who sells a number with a SIP trunk in the country, what such a carrier hands out and what of it goes into Telephony → "Trunks and connections" → "Add provider".

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

In brief#

• A number with a SIP trunk can be bought in Greece, and the venue needs no permits for it. The regulator EETT assigns numbering resources to carriers, and they assign numbers to subscribers: the number always comes from a provider, you cannot get one from the regulator directly.
• Greece is a rare case where trunk parameters are published rather than hidden in a contract. Four carriers keep the host, port, codecs and ready-made Asterisk configuration snippets in their public knowledge base: modulus, Yuboto Telephony, Inter Telecom and VoIP.gr. Their cards are below.
• If you have not picked a carrier yet, take modulus: it is the only one in the country with a step-by-step guide written specifically for FreePBX/PJSIP — the same stack our PBX runs on. The mode is registration (REGISTER), the host is public.
• The main local trap is that an access operator's trunk only lives on that operator's own line. With COSMOTE/OTE the phone system must sit at the declared physical address, with Vodafone the trunk terminates on their router inside the venue's network, and Nova sells its SIP trunk "over a leased line". Such a trunk never reaches a PBX in the cloud — why.
• The second trap is the block on Greek numbers in calls from abroad. Since 19 May 2026 Greek operators must reject an incoming international call that presents a Greek geographic number +302…. If you also need the Greek number for outbound calls into Greece, buy it from a Greek carrier, not from an international one.
• The small things people trip over most: Yuboto uses port 5070, not 5060; inbound channels at Yuboto, Infobell and Hellasfone are bought separately from the numbers.
• Paperwork. The contract is signed with a Greek entity (an AFM tax number is required); none of the carriers we checked publishes a procedure for "a Greek number for a foreign company".

Numbers in Greece#

• The country code is +30, the international prefix for dialling out of Greece is 00. The plan is a closed ten-digit one: the number is always dialled in full, and Greece has no national trunk prefix 0 (unlike Italy, Germany or Serbia).
• Geographic numbers — series 2, exactly 10 digits. The area code is 2, 3 or 4 digits long: 21 for Athens and all of Attica, 231/239 for Thessaloniki, 261 for Patras, 281 for Heraklion, 2821 for Chania, 2841 for Agios Nikolaos; there are 243 codes in total.
• Mobile numbers — 69Α (690, 691, 693–695, 697–699), 10 digits.
• Freephone — 800, shared cost — 801, personal — 70, corporate — 50; premium rate — 806, 812, 825, 896, 899, 901, 909.
• Emergency: 112 (single European number), 100 (police), 108 (coast guard), 166 (ambulance), 199 (fire service). Every provider must keep those calls free of charge, and for that it needs the venue's address — give it when you connect.
• Dialling. Inside the country the ten-digit number is dialled as is (210…, 2310…), abroad — 00 plus the country code. Carriers accept both the national ten-digit form and E.164 with +30 from the PBX.

On the "Lines" tab the number can be entered in any format: the PBX matches the last seven digits. ⚠️ In Attica the area code is only two digits (21), so the subscriber part takes eight digits and does not fit into a seven-digit tail: 21 0 123 4567 and 21 9 123 4567 produce the same tail and become a single line for routing. If the venue has several Athens numbers on one trunk, compare the tails by hand — "Add the number and routing".

⚠️ Emergency numbers are shorter than four digits. The general outbound rule "everything else goes through this trunk" does not pick them up: create separate rules with an explicit pattern for 112, 100, 166 and 199 on the "Outbound" tab.

Who sells a number with a SIP trunk#

The first four rows are the carriers whose parameters are in open documentation: their cards are below. The next four belong to the contract-only section. Three access operators are covered separately, and international providers have their own section.

modulus#

A Greek telecom company founded in 2012: its own cloud PBX, 3CX and a separate "FreePBX" product — a trunk to somebody else's Asterisk is a menu item here, not an exotic request. It is the only carrier in the country with a public step-by-step guide for FreePBX/PJSIP, which is exactly the stack our PBX runs on. For a venue this is the most predictable route: there is nothing to hunt for.

What to enter in the admin panel

What to set up on the provider's side: submit a request → receive the username (email) and the password (SMS) → if the trunk carries more than one number, ask them to enable delivery of the full ten-digit number in the call, otherwise the username arrives instead of the number → give the venue address for 112 calls.

Pitfalls ⚠️ Do not put port "5070" here by analogy with Yuboto — modulus uses the standard port, and the empty field in their guide means 5060. Full-number delivery is enabled on request: 3CX states in its directory that the E.164 format at modulus has to be requested from the carrier. The provider asks for the number in the P-Asserted-Identity header while our PBX sends it in From; if the outbound caller ID collapses into the main number, write to our support — that mode is switched on at the server side ("Outbound calls"). The carrier's codecs are G.722, G.711 a-law, G.729, G.711 u-law: three of the four match the PBX, so there will be no transcoding. Signalling comes from the 185.73.40.0/22 subnet — on a cloud PBX we configure the filters, the venue needs to do nothing. Source: FreePBX based Τηλεφωνικό Κέντρο (PJSIP), 3CX SIP Trunk Providers — Greece — 09.09.2026.

Yuboto Telephony#

An Attica-based CPaaS group (SMS, VoIP, cloud PBX, wholesale voice) where the SIP trunk is a separate "for your PBX" service promised within one day, with free number porting. It is the only carrier in the country with a fully public price list: a Greek geographic number costs €12 per year (10 numbers — €80, 100 — €500), an inbound channel is €12 per year dedicated or €18 per year shared, there is no setup fee; prices include 24% VAT and a 5% levy.

What to enter in the admin panel

What to set up on the provider's side: buy or port a number → buy inbound channels separately (dedicated or shared) → create a device in the panel, that is what produces the username and password.

Pitfalls ⚠️ Port 5070 is the most frequent mistake with this carrier: with 5060 registration simply fails. Channels are counted separately from numbers: "the number exists but no calls arrive" here usually means no inbound channels have been purchased. The incoming call carries the username, not the number — with a single number on the trunk you may skip creating a line altogether, the call is accepted anyway. The codecs are G.711 a-law and G.711 u-law (the Yeastar certification adds G.722), a full match with the PBX. In their own troubleshooting notes the carrier warns that a leftover G.729 in the configuration cuts incoming calls off right after answer — we do not have that codec at all, so this ailment cannot happen. Source: SIP trunk installation guide, SIP Trunking price list — 09.09.2026.

Inter Telecom#

A licensed Greek operator since 2004: fixed VoIP, mobile service, a cloud PBX and wholesale traffic. It is the only one that sells nomadic use of the number itself: the geographic numbers page says "get a Greek geographic number and use it in Greece and abroad, anywhere there is Internet". For a cloud PBX that is the best possible wording — the scheme is declared by the carrier, not assumed by us.

What to enter in the admin panel

What to set up on the provider's side: sign up → create a device in the panel (that gives the username and password) → order a geographic number in the area you need, or port an existing one → ask support to enable G.722 if you want it.

Pitfalls ⚠️ The default codecs are G.711 a-law, G.729, GSM and G.723.1; the PBX speaks the first of them, so the trunk works with no changes, but G.722 (cleaner audio) is only enabled after a support request. The limit on simultaneous calls per device is not stated publicly — ask for it before buying, otherwise a second concurrent call may fail. The parameters page is written for phones and ATAs and has no separate "Asterisk" chapter, but the host and port are the same regardless. Source: VoIP settings, Geographic numbers — 09.09.2026.

VoIP.gr (VoipCom)#

An Athens VoIP provider: a cloud PBX for 2 to 100 extensions, a "SIP lines" service from two channels and DIDs in more than 50 countries. It keeps a public settings page with a ready Asterisk configuration example — a rarity for the country, but the page is clearly old.

What to enter in the admin panel

What to set up on the provider's side: create a SIP device in the panel → buy a Greek number and the number of channels you need → point the number at that device.

Pitfalls ⚠️ Confirm the address with support before you set the trunk up. The settings page dates back to the TrixBox and Elastix era and the host is a bare IP address — if the carrier ever moves, the trunk silently stops registering and the cause takes a long time to find. The only codec enabled in their example is G.711 a-law, which is enough: the PBX speaks it. The carrier asks for the number in the Remote-Party-ID header while we send it in From, so if the outbound caller ID behaves oddly, write to our support. Source: SIP trunk settings — 09.09.2026.

Contract-only carriers#

These carriers do sell a SIP trunk for a third-party PBX as a regular service, but the server address, username and password are only issued after a request or a purchase — so there can be no "what to enter" table here. Ask for the parameters using the list in "What to ask the provider" and type them into the same form. Spell out the main point separately: the PBX sits in the cloud, not on the venue's premises.

• Smart-VoIP — an operator with its own softswitch in a Greek data centre, peering at GR-IX and its own autonomous system; the only one in the country to state both modes explicitly: "authentication: IP-based or username/password". Signalling runs over UDP, TCP or TLS (the first two suit us), codecs are G.711 a-law, G.729 and OPUS, DTMF is RFC 4733. The order of events: you send your current telephony invoice or a description of your PBX → audit → quote → an email with the host, username and password; they configure a third-party PBX remotely free of charge, and porting numbers takes 5–10 business days. ⚠️ They run several interconnect points with failover — if you choose IP authentication, ask for the full list of their signalling addresses, otherwise the PBX will not recognise part of the incoming calls as "from this provider".
• Voiceland — a dedicated business VoIP provider; the Yeastar certification lists it as REGISTER-based, and its codecs (G.711 a-law, G.711 u-law, G.722) match ours exactly. Numbers: geographic ones in every Greek city, non-geographic 800/801 and toll-free in more than 80 countries. The "Voice Unlimited" range (from €15 per month) is aimed precisely at customers who run their own PBX; do not take the "Blue Unlimited" range, that one is for those who have no PBX. ⚠️ When you enquire, say plainly "a SIP trunk to my own PBX", otherwise you will be sold a cloud PBX. Support sends the parameters and the list of platform IP addresses.
• Infobell — a Greek cloud platform with an open price list for channel bundles: SIP 10 — €200 per year (10 channels), SIP 20 — €320, SIP 30 — €440, SIP 60 — €789; every bundle includes G.711 a-law and T.38 fax support. ⚠️ The authentication mode depends on the bundle: SIP 10 and SIP 20 are username/password only, IP authentication starts with SIP 30. The host and port come with the credentials; the bundles are annual, there is no monthly option on the storefront.
• Hellasfone — a business VoIP provider operating since 1999 and the fastest way to get a Greek number without negotiations: an online configurator where you pick the area code out of twenty Greek ones (21 Athens, 231/239 Thessaloniki, 261 Patras, 281 Heraklion, 2821 Chania…), monthly or yearly, with porting of an existing number ordered right there; activation is promised within 24 hours. The base plan is €18 per year, outbound channels are unlimited, inbound channels are a paid add-on (10 channels = €22 per month in the configurator's example), minutes are pay-as-you-go: €0.019 per minute to Greek landlines and €0.059 to mobiles. ⚠️ Neither the host nor the codecs nor the authentication mode are visible before the purchase, which makes it a worse first connection than modulus or Yuboto.

COSMOTE, Vodafone and Nova — why they will not work#

This is the country's main filter, and it is better to hit it before signing anything. All three access operators do have a SIP trunk, but it is designed around their own line to the venue:

• COSMOTE / OTE. The trunk is an account in the operator's IMS (ims.otenet.gr, port 5060, registration with a username shaped like +302XXXXXXXXX@ims.otenet.gr). Integrators who have set it up state it plainly: the phone system must sit at the declared physical address, otherwise the scheme does not work. On top of that, VoIP on the operator's router has to be switched off — otherwise it grabs the same account — and the access codes arrive by SMS with a 15 to 30 minute window to enter them. The operator publishes no documentation and offers no support for connecting a third-party PBX, and responsibility for a hacked trunk and the international traffic it generates rests with the subscriber.
• Vodafone Ελλάδα. The operator has no public SIP trunk page for third-party PBXs; according to engineering community write-ups the trunk terminates on the Vodafone router inside the venue's local network, which acts as a proxy — in that case a cloud PBX has nowhere to register. Check this with your first question to the account manager: "is there a public SIP host that a PBX can register to from the Internet?".
• Nova (United Group). The corporate portfolio offers two variants: "SIP trunk over a leased line" — the same story as COSMOTE and Vodafone — and "SIP trunk via the central SBC infrastructure", which is in theory reachable from the Internet. Find out which one you are being offered before signing; billing is per second with no monthly telephony fee, and support is round the clock.

What to do if the number is already with one of them. Two options: buy a second number from one of the VoIP carriers above and move guest calls to it, or port the existing number. Leaving an access operator also means leaving the dependency on its line — which is exactly the normal route for a cloud PBX.

International providers with Greek numbers#

Greek numbers are sold by Telnyx, Twilio, DIDWW, Zadarma, Bandwidth, Plivo, Sinch, Vonage and didlogic, as well as by Telxi — an international provider certified for Greece by both 3CX and Yeastar (REGISTER mode, codecs G.711 u-law, G.711 a-law, G.722, G.729a, GSM, DTMF RFC 2833, the number delivered in E.164). At Telxi the trunk is provisioned self-service in the portal: the host, username and password appear there and go into the same "Add provider" form.

• They will ask for documents anyway. For a Greek landline number providers require proof of address or business registration — the exact package is shown in the portal when you order. For a foreign company this is often the only route: Greek carriers sign contracts with local entities and ask for an AFM tax number.
• The modes differ. Telnyx and DIDWW offer both registration and a static IP endpoint; Twilio Elastic SIP Trunking works by IP only, so you will need the "Static IP" from the "Server" tab. Cards for Telnyx, Twilio and Zadarma are already in the catalogue when adding a provider: the server address and the mode are filled in for you.
• ⚠️ The key Greek caveat. Since 19 May 2026 a Greek operator must block an incoming international call presenting a Greek geographic number; the only exception is call forwarding while the subscriber is abroad, and even then with the number withheld. The scheme "cloud PBX + a Greek number from an international provider + outbound calls into Greece with that number" breaks against exactly this rule. For receiving calls an international provider is fine; if you also need outbound calls into Greece with a Greek number, take a Greek carrier. The regulator is working on extending the measure to mobile numbers as well.

Porting a number#

• Portability of geographic numbers is mandatory by law — it is written into the national numbering plan, and EETT sets the details of the procedure. The application is filed with the receiving provider, which runs the port.
• Timing and cost. Yuboto declares porting free of charge and handles it right in the order form, Hellasfone puts it into the cart together with the purchase, and Smart-VoIP quotes 5–10 business days with no downtime.
• The subscriber's name must match. The contract is signed by whoever the number is issued to; if the number belongs to the venue, register it on the company straight away — changing the number's owner later is a separate procedure with the losing operator.
• The emergency address must be declared again to the receiving provider: without it a call to 112 or 166 will land in the wrong dispatch centre.
• Porting does not change the area. An Athens number stays an Athens number: if the venue moves to another city, it needs a new number — see the permanent address rule below.

Rules and paperwork#

If it does not work#

1. No registration at Yuboto. Almost always the "Port" field says 5060, while this carrier uses 5070. Check as well that the username is the eight-digit device name from the panel and not the phone number.
2. The number exists but no calls arrive. At Yuboto, Infobell and Hellasfone inbound channels are bought separately from numbers. Check in the panel how many inbound channels are paid for and whether the number points at your SIP device.
3. Calls arrive but always on the same line. The provider sends its own login in the call instead of the dialled number — that is how Yuboto works, and how modulus works with a single number on the trunk. Ask modulus to enable delivery of the full ten-digit number; with Yuboto and a single number you can simply not create a line at all.
4. Two Athens numbers land on the same line. The Attica area code is two digits, the subscriber part is eight, and the PBX matches the last seven: the tails coincide. Split such numbers across different trunks or compare the tails by hand.
5. VoIP.gr does not register. Try port 5070 — the carrier suggests that itself — and confirm with its support that the address 46.4.60.4 is still current: the settings page has not been updated in a long time.
6. A COSMOTE, Vodafone or Nova trunk never comes up at all. This is not a setting but the shape of the service: the trunk is designed around the operator's line at the venue — why, and what to do.
7. The call connects but there is silence. Check the agreed codecs: Inter Telecom enables G.711 a-law, G.729, GSM and G.723.1 by default — the PBX only speaks the first of those, and if the account is configured without it there will be no audio. Infobell declares G.711 a-law only, which is enough.

Causes that do not depend on the country are in "If calls do not go through", together with the SIP trace in the trunk menu. Checking the address and port — "Test the connection", transport and codec requirements — "Network and compatibility".

Frequently asked questions#

Which provider should I pick if nothing is connected yet?#

modulus: it has the only FreePBX/PJSIP guide in the country, the host is a public constant, the codecs match ours and there are just six fields to fill in. If price and self-service matter more — Yuboto Telephony (a number from €12 per year, just do not forget port 5070). If you want a carrier that itself calls nomadic use of the number a normal scenario — Inter Telecom.

My number is with COSMOTE. Can I connect it to the PBX?#

In practice no: their trunk is an IMS account tied to the declared physical address and to their own line, while our PBX sits in the cloud. There are two ways out: buy a second number from a VoIP carrier and move guest calls to it, or port the number — portability of geographic numbers is mandatory in Greece.

Can I take an Athens number for a venue in Chania?#

No. The area code is assigned from the permanent address declared by the subscriber, and using the number outside its area on a permanent basis is not allowed. Nomadic use is permitted, though — so an Athens number belonging to an Athens venue lives happily on a cloud PBX.

Can I take a Greek number from Telnyx or Twilio?#

For receiving calls — yes, every large international provider sells Greek numbers. But since 19 May 2026 Greek operators block an incoming international call showing a Greek number in the caller ID, so outbound calls into Greece with such a number will not go through an international provider. If you need outbound calls too, take a Greek carrier.

Do I need a Greek company to get a number?#

With a Greek carrier — almost always: the contract is signed with a Greek entity, an AFM tax number is required, and a geographic number also needs an address within its area. A foreign company without a Greek registration will find it easier to take a +30 number from an international provider, with their document checks.

How many channels does a venue need?#

A channel is one simultaneous conversation; a restaurant usually needs 2 to 4. Keep in mind that at Yuboto, Infobell and Hellasfone inbound channels are a separate line item: a dedicated channel at Yuboto costs €12 per year, Infobell's smallest bundle is 10 channels for €200 per year, and at Hellasfone outbound channels are unlimited while inbound ones are bought on top.

Sources#

All links checked on 09.09.2026.

Carriers

• modulus — FreePBX based Τηλεφωνικό Κέντρο (PJSIP): https://www.modulus.gr/el/docs/freepbx-based-tilefoniko-kentro-pjsip/
• Yuboto Telephony — SIP trunk installation guide for Elastix, Issabel or FreePBX: https://www.yuboto-telephony.gr/voip-support/telephony-wiki/item/1-odigies-egkatastasis-sip-trunk-se-elastix-i-free-pbx
• Yuboto Telephony — SIP Trunking, price list: https://www.yuboto-telephony.gr/ypiresies/tilefwnika-kentra/sip-trunk
• Inter Telecom — VoIP settings: https://www.intertelecom.gr/fixed/instructions
• Inter Telecom — geographic numbers: https://www.intertelecom.gr/fixed/geografikoi-arithmoi
• VoIP.gr — SIP trunk settings for Asterisk/FreePBX: https://calls.voip.gr/index.php/el/91-help-faq-gr/138-settings-asterisk-gr
• Smart-VoIP — SIP Trunk Greece, technical specs: https://smart-voip.eu/en/sip-trunk/
• Voiceland — services and plans: https://www.voiceland.gr/
• Infobell — High Performance Sip Trunks: https://www.infobell.gr/trunking
• Hellasfone — Business VoIP & SIP Trunk, plan configurator: https://hellasfone.gr/voip-timologisi/pricing-business-voip-el/
• COSMOTE — Unify OpenScape Business: How to Configure SIP Trunk for COSMOTE, Greece (PDF): https://wiki.unify.com/images/b/b3/OSBiz-SIP-Trunk-Configuration-COSMOTE-Greece.pdf
• COSMOTE — Asterisk connection write-up (Primesoft): https://primesoft.gr/ote-voip-sip-asterisk/
• Vodafone Ελλάδα — Business: https://www.vodafone.gr/business/
• Nova — Telephony Solutions: https://nova.gr/epixeiriseis/corporate-solutions/corporate-voice/telephony-solutions
• Telxi: https://telxi.com/

Compatibility directories

• Yeastar — Certified SIP Trunk Providers, Greece: https://www.yeastar.com/itsp-partners/greece/
• 3CX — SIP Trunk Providers, Greece: https://www.3cx.com/partners/sip-trunks/greece/

Regulator and numbering

• EETT — National Numbering Plan (PDF, Greek): https://www.eett.gr/wp-content/uploads/2021/10/FEK_768_B_2007_ESA.pdf
• EETT — Regulation on the management and assignment of numbering resources (PDF, Greek): https://eregistry.eett.gr/docs/ap966_002.pdf
• EETT — measure against fraudulent calls using CLI spoofing: https://www.eett.gr/deltia_tipou/lipsi-metrou-antimetopisis-tilefonikon-kliseon-apatis-me-ti-methodo-cli-spoofing/
• Law 4727/2020 — electronic communications, on the ADAE site: https://adae.gov.gr/adae/nomothetiko-plaisio/nomoi-pou-aforoyn-tis-ilektronikes-epikoinonies/n-4727-2020-psephiake-diakybernese-ensomatose-sten-ellenike-nomothesia-tes-odegias-ee-2016-2102-kai-tes-odegias-ee-2029-1024-elektronikes-epikoinonies-ensomatose-sto-elleniko-dikaio-tes-odegias-ee-2018-1972-kai-alles-diataxeis-phek-a-184-2020

Related pages#

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