Iceland: SIP providers and connecting a number to the PBX

This page continues the general guide to connecting a provider's number to the PBX: that one covers everything that is the same for any operator — the two trunk modes, what to ask the provider, what to type into the form, network requirements and how to test the link. Here comes the Icelandic specifics: who in the country sells a number with a SIP trunk, 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, materials of the regulator Fjarskiptastofa and the requirements for certified trunks; the links are in the "Sources" section.

In short#

• A number with a SIP trunk can be bought in Iceland, and the venue needs no licence. Telephony is sold by an operator that has filed a notification with the regulator; you simply buy a number and a channel from it.
• The market is very small, and local operators hardly sell an "internet trunk to a third-party PBX". At Síminn the corporate trunk is available only to customers who have access to its own IP network; at Sýn (Vodafone Ísland) the trunk historically runs through a gateway into its own MetroNet. Neither path fits a PBX that lives in the cloud.
• On the other hand, exactly one operator publishes its parameters — Síminn — and in exactly the product we need. "Netsími" is an Icelandic 499 xxxx number plus a SIP account for it, which any SIP-capable device can register; Síminn itself writes that the service may be used "hvar sem er í heiminum" — anywhere in the world. That is the fastest route: the Síminn Netsími card.
• If you need the familiar Reykjavík 5xx xxxx number, that means Nova (the only Icelandic operator with a certified SIP trunk for third-party PBXs; parameters come under contract) or an international provider with an Icelandic DID, for example Telxi with published parameters.
• ⚠️ The main local pitfall is the caller ID. Since 2022 Icelandic operators strip the number presentation from a call that arrives in Iceland from abroad showing an Icelandic geographic number (4xx xxxx / 5xx xxxx): the recipient sees "númerslaust" or "óþekkt númer". So outbound calls through a foreign provider with an Icelandic number in "Present as" will arrive without a number — a live caller ID is only possible over an Icelandic operator's trunk.
• The second specific, in contrast, works in our favour: all Icelandic subscriber numbers are seven digits long, while our line is matched by the last seven digits — the tail equals the whole number, so the line collisions seen in countries with eight-digit numbers never happen here.
• No Icelandic operator publishes its codecs. Our PBX speaks G.711 A-law/u-law and G.722; ask the operator to confirm G.711 in writing before signing — see the network requirements.

Numbers in the country#

• The country code is +354, the international prefix is 00. There is no national prefix (no leading zero): the number is always dialled in full.
• The length is 7 digits for all subscriber series 20–99. There is one exception: series 3 (35X XXX XXX) is nine digits long and is issued for SIM devices and machine communication.
• Series: 4 and 5 — general telephony, in practice "geographic" numbers (Reykjavík is 5); 49x xxxx — flökkunúmer, nomadic numbers for internet telephony that are not tied to a connection point; 6, 7, 8 — mobile; 800 — free for the caller; 901–905 — premium rate services, 907–908 — premium with a live operator, 909 — paid automated services; 75 — conferencing.
• Short numbers: 112 is the single emergency number, 116… are the harmonised social services, 18xx are directory services, 1900–1919 are SMS services.
• Dialling: inside the country, seven digits with no prefix; abroad, 00 plus the country code.
• Codecs. The regulator sets no requirements, and no Icelandic operator publishes its codec list. In the outbound rule it is safer to normalise the number to +354…: international providers accept that format only.

On the Lines tab the number may be entered in any form: the PBX matches the last seven digits, so it does not matter whether it arrives as +3545551234, 5551234 or 4991234.

Who issues a number with a SIP trunk#

The first two rows are the providers whose parameters are known in advance; their cards follow below with the "What to enter in the admin panel" table. Then come Nova and the operators that issue parameters under contract; who will not work is at the end.

Síminn Netsími (a 499 xxxx number)#

Síminn is Iceland's historical national operator. "Netsími" is sold as "a home phone in your computer or smartphone", but technically it is an Icelandic number plus a SIP account for it, registered by any device that supports the SIP standard — including our PBX. The operator states it plainly: you get an Icelandic number starting with 499 xxxx and may use the service anywhere in the world, while all calls count as originating in Iceland; the operator itself calls its setup instructions portable to any SIP application.

Ordering goes through Síminn's support desk. There is no connection fee, the monthly fee follows the home-phone price list, and calls to Icelandic geographic and mobile numbers are included. The account's login and password are issued and changed in the operator's self-service portal.

What to enter in the admin panel

What to set up at the provider: order Netsími at the support desk and get a 499 xxxx number → collect or change the SIP account password in the self-service portal → create a trunk in the admin panel with the parameters above → on the Lines tab add a line with this number and keep the "Accepts calls" box ticked → in the outbound rule set "Present as" to the same 499xxxx.

Pitfalls ⚠️ One account means one number: Netsími has no direct-dial range, so ten numbers mean ten trunks. 499 is not a Reykjavík geographic number — the guest will see a nomadic number rather than the familiar 5xx xxxx. The operator's supplementary services (call forwarding and the like) cannot be enabled on this number — our PBX does all of that anyway, which suits us. The operator does not publish its codecs: ask for G.711 in writing, otherwise a call may connect with no audio. Sources: Netsími — 09.09.2026.

Telxi#

An international provider of SIP trunks and numbers in more than 100 countries, certified as a SIP trunk for Iceland in the 3CX list of compatible providers. The model is self-service: register in the portal, pay as you go, no sales cycle needed to start — which makes it the fastest route when the venue has no Icelandic legal entity.

What to enter in the admin panel

What to set up at the provider: register in the portal → buy an Icelandic number and the number of concurrent channels you need → create a SIP trunk → add the numbers in E.164 (+354…) → optionally add our PBX's static IP to the allowed addresses (it is on the "Server" tab, field "Static IP").

Pitfalls ⚠️ Telxi's codecs are G.711 A-law, G.711 u-law, G.729 and Opus, so the set matches our PBX. Numbers arrive in E.164, and the outbound rule is best kept in E.164 too. The main limitation is not technical: the provider is foreign, so an outbound call with an Icelandic geographic number will reach a recipient in Iceland without a number — see "If it does not work". Check the availability and price of Icelandic numbers with sales: they are not spelled out on the public pages. Sources: Telxi trunk setup, SIP Trunking — 09.09.2026.

Nova#

The country's third mobile operator, with its own IP network and 5G; its corporate offering includes leased lines, transit and VoIP services. What matters to us is that Nova is the only Icelandic operator in the list of SIP trunks tested and certified by 3CX — which means a trunk to a third-party PBX really is on sale, not just "a PBX included".

What is known in advance from the requirements for that certified trunk:

• the main trunk number is entered in the national format (example 65553119) — Nova works with numbers without +354;
• outbound calls may present only numbers belonging to your own account; when an inbound call is forwarded through the trunk, the original caller's ID may be preserved;
• Nova has no SIP TLS — and that works in our favour: our PBX does not bring up TLS trunks at all. IPv6, SMS, fax and online self-registration are likewise absent from this trunk.

The SIP host, port, password and codecs are issued when the service is connected, so there is no "what to enter" table here. Order the trunk through the sales team, agree the number of concurrent calls and the numbers, ask for "the parameters as for 3CX" — the operator has a ready template — and ask separately whether our PBX's static IP has to go onto an allow list. The full list of questions for the account manager is in "What to ask the provider".

⚠️ The national number format is the main practical catch: if you normalise the outbound number to E.164, the trunk may fail to recognise its own subscriber. Sources: Nova trunk configuration guide, Nova company services — 09.09.2026.

Operators that issue parameters under contract#

• Síminn — "SIP tengingar". A regular corporate product, "connect your own PBX over SIP", and its service terms (revision 3.0, in force since 01.07.2026) do formally cover a software PBX. But the same terms carry two restrictions that close this path for a cloud PBX: the service is offered only to customers who have access to Síminn's IP network, and it is connected only to equipment that Síminn has tested with a positive result (the tests are run by the equipment supplier following the operator's documents). Capacity is a fixed number of concurrent calls — beyond it the caller hears a busy tone — and no more than 10 numbers per channel, otherwise the operator charges for extra channels. Termination takes effect at the end of a month, with a month's notice.
• Sýn hf. (Vodafone Ísland). The country's second-largest operator. Its "SIP-stofntenging" was described as a PBX gateway connected to its own MetroNet, with a capacity of 4, 10 or 30 speech channels. ⚠️ The fixed-line section has disappeared from the website: as of 09.09.2026 the current corporate storefront offers only mobile service, corporate networks and the Teams and Webex platforms. Whether the trunk is still sold is a question for the corporate service desk. The One Net product will not do: that is their hosted PBX, and connecting a third-party PBX is not part of the description.
• Hringdu. An independent operator: internet, fixed and mobile telephony. Office telephony is sold as a hosted PBX from ISK 2,590 per user per month, with no connection fee and no lock-in period; there is no separate "SIP trunk to your PBX" product on the site. Since this is an operator with its own numbering and its own internet telephony, it is worth asking sales for a SIP account per number separately.
• Hringiðan (Vortex). An internet provider with telephony and an authorised 3CX reseller: it sells a hosted PBX, mobile service over the country's largest network and a simple fixed line. There is no trunk for a third-party PBX on the site — ask support whether they sell a SIP account per number instead of a seat in their PBX.
• Snerpa. A regional operator in the Westfjords (Ísafjörður): internet, fibre, mobile service and internet telephony "over the internet" at ISK 1,990 per month, plus sales and support of 3CX. The SIP account parameters are not published. ⚠️ The price list carries an explicit reservation: the operator may shut off an unlimited package if the service is used for automated dialling — keep that in mind if you plan outbound campaigns.

Ask all five the same set of questions — "What to ask the provider". The required minimum: server address and port, transport, authorisation mode (registration or by IP), codecs and the number format in an inbound call.

Who will not work#

• Operators' hosted PBXs — One Net at Sýn, Síminn's cloud PBX, the 3CX-based packages from Hringdu, Hringiðan and Snerpa. These are "a PBX instead of yours": the operator keeps the switch on its side, and these products carry no outward trunk. If the venue is already on such a package, the number still sits with the operator — bringing it to us requires a separate trunk or number porting.
• Integrators with no numbering of their own — Boðleið (3CX, Teams, Totalview, SMS gateways) and ASTRA (3CX on lease or by licence). They do not sell numbers, and the trunk still comes from an operator. They are useful as local contractors, though: they can order numbers from Nova or Síminn and hand over ready trunk parameters.
• Systems integrators — Sensa (Teams, Webex), Advania, Origo, Svar (Teams, 3CX, Enreach, XCALLY, Zoho Voice). They deploy third-party platforms on top of operator numbering; they have neither numbers nor trunks of their own.

International providers with Icelandic numbers#

⚠️ A caveat that matters for this whole chapter. Since 2022 Icelandic operators strip the number presentation from calls that arrive in Iceland from abroad with an Icelandic geographic caller ID: the recipient sees "no number" or "unknown number". The regulator's reasoning is that "Icelandic general telephone numbers are to be used in Iceland only". An international number is therefore good here mostly as an inbound one; if it matters that the guest sees a number when calling back, the trunk has to come from an Icelandic operator. Separately: outbound SMS from an Icelandic mobile number through a foreign interconnect is also stopped by the operators.

Trunk parameters at international services are the same for every country — see the provider's card in the catalogue when adding a trunk; only the Icelandic specifics are below.

• Telnyx — Icelandic local and toll-free numbers. Document checks are light: an address anywhere in the world (street, building number, postal code, city, country), and for a company the name and the representative's name; activation takes about 72 hours. The fastest route for a foreign tenant.
• Twilio — Icelandic local, national and mobile numbers, and the provider is marked as preferred in the 3CX list of compatible trunks for Iceland. The checks are strict, though: the address must be Icelandic both for a company (a business register extract plus proof of address) and for an individual (an identity document, proof of address, the national identifier kennitala).
• DIDWW — Reykjavík +354 (5) numbers, toll-free +354 800 and international toll-free; for Reykjavík numbers inbound calls and local trunking are supported. A document pack for the company is required: a certificate of incorporation, the representative's ID and proof of the company's address.
• Zadarma — Reykjavík (code 5): free to set up, USD 13.5 per month (USD 9 when paid yearly); a toll-free 800 number costs USD 60 to set up and USD 19.2 per month. Documents: a copy of an identity document, both sides, and a current address. Two lines come with the number; more cost extra.
• Telxi — the same kind of international provider, but with published parameters; its card is above.

Common to all international providers: outbound calls may present your own number only, and a call to 112 through an international number generally does not work — it is a separate service. The venue needs either a local trunk or an ordinary mobile phone for emergencies.

Number porting#

• The right to port is laid down in the regulator's rules (rules on number and service porting in public networks, nr. 1112/2022). The application is filed by the receiving operator.
• The deadlines are strict: a fixed or mobile number is ported no later than one working day after the donor operator receives the request, and in any case no later than ten working days from the application.
• ⚠️ 49x xxxx numbers cannot be ported. When nomadic numbers are assigned, the numbering rules add an explicit reservation: they are not transferred to another service. So Síminn's Netsími number is not "yours forever" — it is tied to that service. If the number has to stay with the venue when the operator changes, take a geographic 5xx xxxx number.
• The number belongs to the operator, not to the subscriber: an assignment grants a right of use, not ownership. Numbers may be handed over to a third party, but only to an operator registered in Iceland that has a switch in the country.
• If an operator ceases trading, unused ranges return to the regulator within a month, while the regulator together with other operators keeps numbers already in use in service — so the risk of "the number dying with the provider" is low.

Rules and documents#

If it does not work#

1. The operator answers "the trunk works only inside our network". That is not an excuse: Síminn's corporate trunk is offered only to customers with access to its IP network and only on equipment it has tested, and Sýn's gateway is attached to its own MetroNet. For a cloud PBX use Síminn's Netsími, Nova or an international provider.
2. Netsími does not register. The operator's own instructions select TCP as the transport. If registration does not come up over UDP, switch the "Transport" field to TCP and press "Test link"; the port is not published on the service page, so 5060 is a sensible default rather than a fact from the contract.
3. Inbound calls arrive but no line is selected. With Netsími one account equals one number, and that number is what arrives in the call. If there are several numbers, each needs its own trunk: this service has no direct-dial range.
4. Outbound calls go through but the recipient sees no number. That is an Icelandic specific rather than a fault: a call arriving in Iceland from abroad with an Icelandic geographic caller ID is delivered by the operators without number presentation. The only cure is a trunk from an Icelandic operator.
5. Outbound calls are rejected or leave with the wrong number. The number format differs between providers: Nova expects the national one (65553119), Telxi expects E.164 (+354…), Netsími expects the number 499xxxx itself. Bring the number in the outbound rule to your provider's format and present only numbers from your own contract.
6. The call connects but there is silence. The codecs did not match: Icelandic operators do not publish them, and our PBX speaks G.711 A-law/u-law and G.722. Ask the operator to enable G.711 and confirm it in writing — network requirements.
7. "Busy" after the second call. Capacity here is sold in steps: 4, 10 or 30 channels at Sýn, and a fixed number of concurrent calls with a ceiling of 10 numbers per channel at Síminn. Agree the number of channels before signing.

Causes that do not depend on the country are in "If calls do not go through".

Frequently asked questions#

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

Síminn Netsími: it is the only Icelandic operator with published SIP parameters, connection is free, setup happens on the day of the request, and the number stays Icelandic, which means caller ID works on outbound calls. If a geographic 5xx xxxx number is a must — Nova (through the sales team) or Telxi with published parameters and self-service.

Why does a Netsími number start with 499 and not with 5?#

49x xxxx is the nomadic series of the Icelandic numbering plan: such numbers are not tied to a connection point, which is why the operator allows the service to be used from anywhere in the world. The flip side: the guest sees something other than the familiar Reykjavík 5xx xxxx, and such a number cannot be ported to another service.

Can I get an Icelandic number if the company is registered elsewhere?#

With local operators, hardly: the contract is signed against an Icelandic registration. International services differ: Telnyx accepts an address in any country in the world, Zadarma asks for an identity document and a current address, while Twilio requires a specifically Icelandic address for Iceland. The fastest route without an Icelandic presence is Telnyx or Telxi, with all the caveats about caller ID.

Why do most Icelandic operators have no "what to enter" table?#

Because they do not publish trunk parameters: the server address, port, authorisation mode and codecs are issued by an engineer during connection. On a market this small that is the norm. Budget a separate step for finding them out and ask the questions from "What to ask the provider" before signing.

Do I need to do anything about line matching on seven digits?#

No, and this is a rare case where a country's numbering helps us. Icelandic numbers are seven digits long, so the tail equals the whole number and two different numbers never merge into one line — unlike in countries with eight-digit numbers.

Will calls to 112 work?#

Over an Icelandic operator's trunk, yes: the operator is required by law to pass 112 through free of charge. Over an international number (Telnyx, Twilio, DIDWW, Zadarma, Telxi), generally no — that is a separate service. Keep an ordinary mobile phone at the venue for emergencies.

Sources#

All links checked on 09.09.2026.

Providers

• Síminn — Netsími (SIP account parameters, the 499 xxxx number, service terms): https://adstod.siminn.is/home/netsimi
• Síminn — terms of the "SIP tengingar" service, SKM-10277, rev. 3.0: https://static.siminn.is/web/terms/SKM-10277+SIP+tengingar+hja+Simanum.pdf
• Síminn — index of terms and forms: https://www.siminn.is/skilmali/sip-tengingar-hja-simanum
• Nova — SIP trunk configuration guide (national number format, caller ID, no TLS): https://www.3cx.com/community/threads/nova-sip-trunk-configuration-guide-iceland.82955/
• Nova — company services: https://www.nova.is/en/companies/company-services
• 3CX — list of SIP trunk providers for Iceland: https://www.3cx.com/partners/sip-trunks/iceland/
• Sýn / Vodafone Ísland — "Fastlínutækni", SIP-stofntengingar (archived page of 07.07.2022): https://web.archive.org/web/20220707155917/https://vodafone.is/fyrirtaeki/fastlina/fastlinutaekni/
• Sýn — One Net (hosted PBX): https://www.syn.is/fyrirtaeki/samskiptalausnir/one-net
• Hringdu — services for companies: https://hringdu.is/fyrirtaeki
• Hringiðan — telephony for companies: https://hringidan.is/fyrirtaeki/simathjonusta/
• Snerpa — 3CX and price list: https://www.snerpa.is/3cx_simkerfi/, https://www.snerpa.is/verdskra/
• Boðleið — 3CX: https://www.bodleid.is/3cx
• ASTRA — 3CX: https://www.astra.is/3cx-simkerfi/
• Telxi — connecting a SIP trunk to a third-party PBX: https://intergo.freshdesk.com/support/solutions/articles/43000707929-how-to-connect-your-sip-trunk-to-3cx-or-other-pbx
• Telxi — SIP Trunking: https://telxi.com/sip-trunking/

Regulator and law

• Lög nr. 70/2022 um fjarskipti — general authorisation, emergency calls, call recording: https://www.althingi.is/lagas/nuna/2022070.html
• Reglur nr. 960/2023 on numbers and number ranges (number length, series, nomadic 49x): https://www.fjarskiptastofa.is/library?itemid=ff56dcbb-f1f2-4a16-a87f-46105bf2dada
• Fjarskiptastofa — "Um svik í fjarskiptum", overview, March 2025 (caller ID stripped from international calls): https://www.fjarskiptastofa.is/library?itemid=48477fd2-aba7-4b48-9dfc-6ac190b6c693&type=pdf
• Reglur nr. 1112/2022 on number and service porting: https://island.is/stjornartidindi/nr/c1ea3197-6764-467c-904f-d7bfb8ea6008

International providers

• Telnyx — Iceland DID requirements: https://support.telnyx.com/en/articles/3739458-iceland-did-requirements
• Twilio — Iceland regulatory guidelines: https://www.twilio.com/en-us/guidelines/is/regulatory
• DIDWW — Iceland phone numbers: https://www.didww.com/phone-numbers/all-phone-numbers/Iceland/Local
• Zadarma — Iceland numbers: https://zadarma.com/en/tariffs/numbers/iceland/

Related pages#

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