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SIP trunk in Kenya: what it is, what it costs and how to set one up
10 November 2026 · 8 min read
The short answer
A SIP trunk is a phone line delivered over the internet to a PBX, carrying your numbers and calls. On 10 November 2026, a Sautikit number works as the trunk for any PBX that registers with a username and password: KES 500 a month, no trunk fee, free incoming calls. A team without a PBX can use SautiDesk instead.
A SIP trunk connects an office phone system, called a PBX, to the phone network. In Kenya the cost is made of a few lines: the number, the trunk itself, the call minutes and, for most trunks, a channel count that limits how many calls run at once. A Sautikit number removes two of those lines. It is KES 500 a month with no set-up fee and no trunk fee, incoming calls are free, and outgoing calls are KES 3.00 a minute billed per second. SautiDesk, the call centre built on the same voice service, needs no trunk at all because agents answer in the browser.
What is a SIP trunk?
SIP (Session Initiation Protocol) is the language internet phone systems use to start and end calls. A SIP trunk is a phone line that uses it. Your PBX, which could be 3CX, FreePBX, Yeastar, Grandstream UCM or Avaya, is the system that rings your staff. The trunk is the pipe that brings calls in from customers and sends calls out to them, with your Kenyan numbers attached.
There are two ways a PBX connects to a trunk. In a register-based trunk the PBX signs in to the provider with a username and password, the way a desk phone does, so the PBX can sit anywhere with internet access. In an IP-based trunk the provider sends calls to a fixed IP address. The guide linked below covers the register-based kind, and that is the kind most PBX software calls a “register trunk” or “SIP trunk with registration”.
What a SIP trunk costs in Kenya
When you compare trunks, ask about every line in the table. A quote that shows one of them can leave the others out.
| Cost line | On a Sautikit number |
|---|---|
| Number | KES 500 a month, no set-up fee |
| Trunk fee | None. The KES 2,000 a month trunk fee applies only if you bring your own carrier |
| Incoming calls | Free |
| Outgoing calls | KES 3.00 a minute to Kenyan numbers, billed per second after the call is answered |
| Channels (calls at once) | No channel count to choose: you do not buy 4, 8 or 16 up front |
| Contract | None, the number is monthly |
| Payment | A prepaid balance in shillings, topped up by M-Pesa or card |
Billing per second matters on short calls. A 40-second call costs KES 2.00, not a full minute. Unanswered calls cost nothing, because billing starts when the far end answers.
A worked month for a 12-person office
Take an office PBX with one customer line. The team makes 2,000 minutes of outgoing calls to Kenyan numbers in the month and takes any number of incoming calls.
| Line | Sautikit trunk |
|---|---|
| Number | KES 500 |
| Trunk fee | KES 0 |
| 2,000 outgoing minutes | 120,000 seconds × KES 0.05 = KES 6,000 |
| Incoming calls | KES 0 |
| Total for the month | KES 6,500 |
If the office wants a second customer number, such as a sales line, each additional number is another KES 500 a month with its own credentials.
How to set up a SIP trunk on your PBX
These steps use a Sautikit number and a register-based trunk. The full guide, with every field, is Use a Sautikit number as a SIP trunk.
- Claim a number at sautikit.com. It costs KES 500 a month and is live in seconds.
- In the console open Numbers, pick the number, go to the SIP & Devices tab and add a device named after your PBX. Copy the username and password straight away.
- In your PBX, create a SIP trunk of the register type and enter the settings in the table below.
- Save, and check the trunk status. Most PBXs show “registered” within a minute.
- Add an inbound route that sends calls from this trunk to an extension, ring group or menu, and an outbound route that sends the calls you choose out through it.
- Test both ways: dial your own mobile from an extension and check it shows your Sautikit number, then call the Sautikit number from your mobile.
| PBX field | Value |
|---|---|
| Trunk type | Register trunk (registration with username and password) |
| Server, host, registrar or proxy | sip.sautikit.com |
| Port | 5080 |
| Domain or realm | sip.sautikit.com |
| Transport | UDP |
| Username and authentication name | Your generated username, the same value in both |
| Password | Your generated password |
| Outbound proxy | Leave empty |
Why a SIP trunk does not register
- The port is wrong. 5060 is the usual SIP default and many PBXs fill it in for a new trunk. Sautikit listens on 5080, and a trunk left on 5060 never registers.
- The transport is not UDP. Set it to UDP.
- The username or password is wrong. Copy the password again from the device’s SIP setup, without a stray space. The username and the authentication name are both the generated username, not the phone number.
- Another device is using the same credential. Each credential is for one device. Give the PBX its own, and give every desk phone or app another.
- The router interferes. A router with SIP ALG switched on can cause one-way audio and dropped calls. Sautikit has a guide on how to turn off SIP ALG.
Caller ID on this trunk is the Sautikit number the credential belongs to. A PBX cannot present a number you do not own. To show a second number, claim it and give it its own trunk.
Already have numbers with another carrier?
Sautikit also connects a trunk you already hold. You enter your carrier’s details in the console and add the numbers you own. That trunk is KES 2,000 a month from your balance, and numbers you bring carry no rent on Sautikit. The setup is covered in the Numbers concepts page and the Africa’s Talking worked example. Compare the full monthly bill before you decide: Africa’s Talking vs SautiDesk shows one.
Do I need a SIP trunk at all?
A trunk is for businesses that run a PBX. A team whose job is answering customers does not need one. On SautiDesk each agent answers your Kenyan business number in the browser with a headset. Calls ring the next free agent in a call queue, a missed call becomes a ticket with an owner, and the number is KES 500 a month. There is no PBX to run and so no trunk to configure.
The voice service underneath SautiDesk is Sautikit, so the two share the same Kenyan numbers and rates. A business that keeps its PBX and wants a number can start on Sautikit, and a business that wants the whole desk can start on SautiDesk. The PBX buyer’s guide explains how to choose between them.
Start on SautiDesk
- Pick Basic at KES 1,000 per person a month, or Pro at KES 3,000 per person if you want several queues, reports and calling campaigns.
- Add your people. Each person is billed by the month.
- Choose a Kenyan number at KES 500 a month for calls and SMS.
- Top up your balance by M-Pesa or card. Incoming calls are free and outgoing calls are KES 0.05 per second.
- Sign in with a headset and take the first call. No trunk, server or desk phone is needed.
See all plans and usage rates on the pricing page, and the related guides 3CX pricing in Kenya and IVR menus explained.