Sri Lanka: SIP providers and connecting a number to your PBX

This page continues the general guide to connecting a provider's number to your PBX, which covers what is the same in every country — the two trunk modes, what to ask your operator, what to enter in the provider form, how to test the connection and what your network must pass. Here — only what is specific to Sri Lanka.

The data was collected on 10 September 2026 from operator websites, documents of the regulator TRCSL (numbering plan, licence register, VoIP unblocking procedure) and the pages of international providers; the links are in the "Sources" section.

In brief#

• SIP in Sri Lanka is closed by default — by every operator, on the regulator's instruction. TRCSL states that VoIP is "not allowed … for the purpose of to by-pass international telecommunications services" and that the listed VoIP applications therefore "are blocked by all the operators"; the list includes SIP and its ports "TCP/UDP 5060-5061". Unblocking is a standard procedure, but a written one: an application from the customer through their own operator to TRCSL. It is the first step of the connection, not a formality.
• The only operator with a named product is SLT-Mobitel: "SIP Trunk — Reliable SIP Connectivity to your on prem-IP PBX". But in the operator's own words the service is "provided over a Virtual Private network" — the trunk arrives over SLT's private network, while our PBX sits in a cloud abroad. The first question for the sales rep is whether the trunk can be delivered to a public static IP outside the country.
• The most practical local route to a number on a cloud PBX is TechGates: a reseller that openly offers Sri Lankan virtual numbers "for pure business purposes" with calls received "anywhere in the world". Like everyone in the country, it hands out the parameters only at activation.
• Nobody publishes trunk parameters — no host, no port, no authentication mode, no codecs. Ask exactly three things: UDP or TCP, not TLS only; registration or our static IP on a whitelist; G.711 or G.722, not G.729 only.
• The market has shrunk: Airtel Lanka ceased to exist on 30.08.2024 (its base moved to Dialog), and Lanka Bell closed in 2024. Voice is sold by three groups — SLT-Mobitel, Dialog and Hutch. Twilio and DIDWW do not sell Sri Lankan numbers.
• The numbering trap. A line is matched by the last seven digits, and the subscriber number here is exactly seven digits: 011 234 5678 (Colombo) and 081 234 5678 (Kandy) give the same tail and merge. One number per venue is safe; with several numbers from different zones, check the tails by hand.

Numbers in the country#

Country code — +94, national prefix — 0, international prefix — 00. The national number is exactly 10 digits for every service: a three-digit area code (with the leading 0) and a seven-digit subscriber number. In "Lines" the number is entered as in E.164 — +94 and nine digits without the leading zero.

• No Sri Lankan provider publishes the form in which the number arrives in an incoming call — most likely 0XXXXXXXXX or 94XXXXXXXXX. On the first connection look at the SIP trace and create the line from what actually arrives.
• Number tails. The subscriber part is 7 digits — exactly as many as the PBX matches in a line. Numbers within one zone are told apart correctly; numbers from different zones with the same last seven digits — and a landline 011 123 4567 with a mobile 077 123 4567 — are indistinguishable. Put such numbers on different trunks or route by trunk rather than by line.
• Emergency numbers under the numbering plan: 110 — Emergency and Rescue Service, 119 — police, 112 — police from mobiles, 118 — National Help Desk, 117 — Disaster Management Centre. They cannot be dialled through an international provider's number — keep an ordinary phone or mobile on shift.

The key condition: SIP unblocking through TRCSL#

The telecom regulator TRCSL publishes both the rule and the technical blocking parameters on its "Numbering → VOIP Unblocking" page. In the table "Technical Parameters to block the VOIP application" the first row names the link type — "symmetric broadband, leased line, international private leased circuit" at 1 Mbps and above — and the third names the protocols, including "SIP … SIP (TCP/UDP 5060-5061)". So on a typical corporate link SIP on 5060 is closed — and it looks like "the network does not let it through", while in fact it is a regulatory rule.

Who may request unblocking (TRCSL list): licensed operators and internet service providers, "any customer who communicate with his own officers within the country", customers in international logistics, international banking, IT development and support, and "any other application which is not used to establish and terminate illegal voice bypass".

How it is filed:

1. Fill in the form "Application for unblocking of VOIP facilities" (version of 16.07.2025, link in "Sources").
2. Submit it through your telecom operator to TRCSL with a justification.
3. After approval the original goes to the operator and a copy to the customer.

How to word it. A cloud PBX for internal communication between venues and for taking guests' calls — not "cheap international calls": the rule is written precisely against bypassing international interconnect. The regulator does not publish a review period — plan for weeks, not days.

The block is not limited to the trunk: SIP phones and the staff app that reach the cloud PBX over the venue's internet hit the same closed ports. TRCSL is also mid-reform — a roadmap for a unified licence (Unified Licensing Framework) has been published; how it will affect VoIP blocking has not been announced.

Who sells a number with a SIP trunk#

Below are the SLT-Mobitel and TechGates cards with what to enter in the admin panel, and a short Dialog card; the rest are in "Who else sells telephony in the country". The full list of questions for the account manager is in "What to ask your provider".

SLT-Mobitel — SIP Trunk#

The national operator (the combined SLT and Mobitel brand) with fixed, mobile and international licences. The only one in the country that sells a trunk to the customer's PBX as a named product: Business → Voice & Collaboration → SIP Trunk. The page promises: "SIP connectivity enables, on-premises PBXs to connect to PSTN network", a "number block" sized to the PBX lines, "Multiple sessions", "Pilot Number", "TRC approved short code service", "Redundant SIP connectivity for load balancing/failover", and enabling or disabling international calls. Enterprise contract only; SIP trunk prices are not published.

What to enter in the admin panel (Telephony → "Trunks & pairings" → "Add provider", card "SIP trunk (your own provider)"):

What to set up on the provider side:

1. Agree in writing that the trunk will be delivered outside SLT's private network to the PBX's public static IP ("Server" tab → "Static IP"). This is the key question; the answer "VPN only" closes the topic.
2. File the VoIP unblocking application to TRCSL through SLT (see the section above).
3. Codecs G.711 a-law/u-law or G.722, not G.729 only.
4. Route the allocated number block to the trunk and find out in which form the number arrives in the request.
5. Allow media to the PBX address, UDP ports 10000–20000; agree the number of simultaneous sessions.

Pitfalls ⚠️

• "Over a Virtual Private network" is a delivery model, not a marketing phrase. In the standard setup the trunk comes to the customer's premises over SLT's link, and a PBX in a foreign cloud does not fit that design. Until the sales rep confirms delivery to a public IP in writing, it is too early to plan the connection.
• E1 trunks are still offered (R2/PRI, 30 channels) — that is the route for a PBX located in Sri Lanka itself, not for a cloud one.
• A Lanka Bell number now belongs to SLT. If the venue still has a number from the closed operator, talk to SLT about the trunk and check whether the number changed during the transfer.

Sources: SLT-Mobitel — SIP Trunk · Trunking Services · Voice & Collaboration — 10.09.2026.

TechGates — SIP Trunking and virtual numbers#

A Colombo integrator of IP PBXs and call centres (+94 114 813 513, sales@techgates.lk) that also sells its own SIP trunk with virtual numbers. The key sentence for us: "Sri Lankan virtual numbers are available for pure business purposes. … You can receive incoming calls just right in to your smart phone or IP phone anywhere in the world. All you have to do is connect them to the internet". It is the only local provider that publicly promises a Sri Lankan number for a PBX outside the country. Terms: "Instant Setup", "Minimum monthly commitment", prices — "Contact us for pricing".

What to enter in the admin panel:

What to set up on the provider side: order a "Sri Lankan virtual number" → say the PBX is Asterisk on its own server with a public static IP → ask for G.711 a-law/u-law → confirm the number format in incoming calls (0… or 94…) → ask them to send media to the PBX address.

Pitfalls ⚠️

• This is a reseller, not a TRCSL licensee. The number comes from a partner operator, so both quality and the number's longevity depend on someone else's contract.
• The site is built around cheap outbound international calls — exactly the scenario the VoIP blocking rule is written against. Confirm in writing that the scheme is lawful for the specific venue, especially outbound calls into local networks with such a number.
• Not a single public parameter. Test with "Test connection" right after entering the credentials.

Source: TechGates — SIP Trunking and Virtual Numbers — 10.09.2026.

Dialog Enterprise — on contract#

The country's largest telecom group: Dialog Axiata PLC (mobile and international licences) and Dialog Broadband Networks (fixed services, internet, leased circuits). After the merger on 30.08.2024 the Airtel Lanka customer base moved here. The "Fixed Telephony Solutions" page lists "IP telephony and hosted PBX", "Hybrid voice solutions" and "Smart PABX", alongside Bizpack Unlimited, the cloud Hosted PABX on 3CX (together with Simsyn) and Dialog Operator Connect for Microsoft Teams. The words "SIP trunk" do not appear on these pages — which is why there is no "What to enter" table here: if a trunk is granted, the account manager provides the parameters.

How to order. The "Get in Touch" form on business.dialog.lk; Dialog Axiata PLC, No. 475, Union Place, Colombo 00200, +94 777 887 887. Word the request directly: "SIP trunk to our own PBX at a public static IP abroad" — otherwise you will be offered their own cloud PBX.

What to ask: the same questions as in the overview, plus trunk delivery to a foreign static IP, the VoIP unblocking application through Dialog, G.711/G.722 codecs, routing the number to the trunk, media on UDP 10000–20000 and the number of channels.

Pitfalls ⚠️ If the venue already runs on Dialog Hosted PABX or Teams, moving to us means changing the product at the operator, not "just adding a trunk".

Sources: Fixed Telephony Solutions · Bizpack Unlimited · Dialog Operator Connect — 10.09.2026.

Who else sells telephony in the country#

International providers with Sri Lankan numbers#

Cards for popular international providers are already in the catalogue when you add a provider — the server address and mode fill in automatically. What is specific to Sri Lanka:

• Twilio says it plainly on its Sri Lanka page: "Although we don't have voice enabled numbers in this locale, you can use numbers from over 90 other locales". Outbound calls to the country only — from $0.2846 per minute.
• DIDWW does not have Sri Lanka among its 93 coverage countries; its Sri Lanka page is about outbound calls, not local numbers.
• Plivo — outbound routes only, from $0.2180 per minute; no local numbers. Its per-network breakdown still lists Airtel and Etisalat, which no longer exist in the country.
• Telnyx advertises Sri Lankan numbers — according to its page on 10.09.2026, from $30 per month. Check availability by searching for a specific number in the portal.
• CommPeak advertises four kinds of +94 numbers (geographic, non-geographic, mobile, toll-free) with document checks "if required" — confirm the country requirements when ordering.
• PBX.IM advertises numbers in Colombo, Kandy and Galle, but refers to "Airtel Sri Lanka" (gone since 30.08.2024) and to another country's regulator — the text is a template and cannot be relied on.
• Global Call Forwarding, United World Telecom, TollFreeForwarding — forwarding services: toll-free (at Global Call Forwarding from $98.95 per month), mobile and landline numbers forwarded to a SIP address. This is not a trunk: incoming calls arrive, but you cannot call out from such a number.
• Common to all. A Sri Lankan number from a foreign provider reaches the PBX from abroad. For incoming calls this usually works; outbound calls with such a number into local networks are exactly the bypass the VoIP blocking rule targets. A venue that calls its guests itself needs a local operator, not a reseller.

Number porting#

• There is no number portability in the country. A consortium of operators, Lanka Number Portability Services, was set up for it and the rules were approved, but the launch date has slipped several times; as of 10.09.2026 no launch had been announced — check with the operator.
• The number is tied to the operator: you cannot switch from SLT to Dialog and keep the number. Choosing the trunk operator is a decision for years.
• A short code (1XXX, SLT's "TRC approved short code service") is issued by the regulator through the operator; it is lost when you change operators.
• A Sri Lankan number cannot be moved to a foreign provider — there is no porting even between local operators.

Rules and documents#

If it does not work#

1. The trunk or SIP phones do not get through although everything is entered correctly. Most likely this is the regulatory block on SIP ports 5060–5061 on the link, not a configuration error. Check whether the VoIP unblocking application filed through the operator has been approved.
2. SLT-Mobitel: trunk ordered, unreachable from the cloud. By default the trunk is delivered over SLT's private network. Confirm that the contract allows delivery to your public static IP — it is shown on the "Server" tab.
3. The call connects but there is no audio. Nobody here publishes codecs: ask for G.711 and G.722. A "G.729 only" trunk looks healthy and gives no sound. The second common cause is media not being allowed to the PBX address.
4. A call to the second number is handled by the first number's scenario. The subscriber number is seven digits, and 011 234 5678 and 081 234 5678 merge into one line. Put such numbers on different trunks.
5. A number from an old guide does not work. Airtel Lanka and Lanka Bell closed in 2024; look for their numbers and trunks at Dialog and SLT-Mobitel respectively.

Other typical causes are in the general section of the overview; to check the address and port — "Test connection".

FAQ#

Who should I get a number from in Sri Lanka first?#

Start with SLT-Mobitel: it is the only operator with a "SIP Trunk" product for the customer's PBX. Ask first whether the trunk can be delivered to a public static IP abroad. If the answer is "private network only", the next step is Dialog Enterprise with the same wording, and for taking incoming calls on a cloud PBX — a TechGates virtual number.

Why does SIP not get through if the provider has set everything up?#

Because in Sri Lanka SIP is closed on the regulator's instruction: TRCSL publishes a list of blocked applications and ports, and SIP (TCP/UDP 5060–5061) is on it. To open the ports, the venue files a VoIP unblocking application with TRCSL through its operator on the official form. Without approval neither the trunk nor SIP phones on a corporate link will work.

Can I make do with an international provider?#

Only partly. Twilio and DIDWW have no Sri Lankan numbers; Telnyx and CommPeak advertise them — check by ordering a specific number. Incoming calls through such a number usually work, but outbound calls with it into local networks are the very interconnect bypass the blocking rule targets. A venue that calls its guests itself needs a local operator.

Can I keep my number when I change operator?#

No. Sri Lanka has no number portability: the project started long ago, but as of 10.09.2026 no launch had been announced. The number stays with the operator that issued it, so choose the trunk operator with years in mind.

Do emergency calls work through such a number?#

Not through an international provider's number: 110, 119 and the other emergency codes are local operator services. Always keep an ordinary phone or mobile on shift.

Sources#

All links checked on 10.09.2026.

Regulator

• TRCSL — Numbering / VOIP Unblocking (SIP port blocking, categories and unblocking procedure) — https://www.trc.gov.lk/pages_e.php?id=121
• TRCSL — Application for unblocking of VOIP facilities, form of 16.07.2025 — https://www.trc.gov.lk/content/files/download/VoIP_Application_16.07.2025.doc
• TRCSL — Sri Lanka Numbering Plan, 10-digit Open-Numbering System (PDF) — https://www.trc.gov.lk/content/files/numbering/numberingmanual.pdf
• TRCSL — Licensing → System Licence, register of current licences and the Unified Licensing Framework — https://www.trc.gov.lk/licensing/pages_e.php?id=13
• Data Protection Authority of Sri Lanka — https://www.dpa.gov.lk/

Operators and providers

• SLT-Mobitel — SIP Trunk — https://www.slt.lk/en/business/sip-trunk
• SLT-Mobitel — Trunking Services — https://www.slt.lk/en/package-and-section-categories/trunking-services
• SLT-Mobitel — Voice & Collaboration — https://www.slt.lk/en/business/voice-collaboration
• Dialog Enterprise — Fixed Telephony Solutions — https://business.dialog.lk/products-services/converged-communications/fixed-telephony-solutions/
• Dialog Enterprise — Bizpack Unlimited — https://business.dialog.lk/products-services/converged-communications/bizpack-unlimited/
• Dialog Enterprise — Dialog Operator Connect — https://business.dialog.lk/products-services/converged-communications/dialog-operator-connect/
• TechGates — SIP Trunking and Virtual Numbers — https://www.techgates.lk/sip-trunking-and-virtual-numbers/
• Simsyn — Cloud PABX Solutions — https://simsyn.com/solutions/cloud-pabx-solutions/
• Fennix — 3CX — https://fennix.lk/3cx/
• Hutch Sri Lanka — https://www.hutch.lk/
• Tata Communications — Global SIP Connect — https://www.tatacommunications.com/solutions/unified-communications/global-sip-connect/

International providers

• Twilio — SIP Trunking pricing, Sri Lanka — https://www.twilio.com/en-us/sip-trunking/pricing/lk
• DIDWW — SIP Trunking Services in Sri Lanka — https://www.didww.com/voice/global-sip-trunking/Sri_Lanka
• DIDWW — coverage list — https://www.didww.com/coverage-and-prices/coverage
• Plivo — SIP Trunking pricing, Sri Lanka — https://www.plivo.com/sip-trunking/pricing/lk/
• Telnyx — Buy Sri Lanka virtual phone numbers — https://telnyx.com/phone-numbers/sri-lanka
• CommPeak — Sri Lankan DID Number — https://www.commpeak.com/services/virtual-numbers-dids/sri-lanka/did-numbers
• Global Call Forwarding — Sri Lanka Virtual Phone Numbers — https://www.globalcallforwarding.com/services/virtual-phone-numbers/sri-lanka-virtual-phone-numbers/

Related pages#

• Connecting a provider's number to your PBX — general steps, trunk modes, network, connection test.
• SIP phone setup — how to attach desk phones, DECT and gateways to extensions.