VoIP • Telkom migration

How to move your Telkom fixed lines to VoIP

A practical, step-by-step playbook for switching a Telkom landline or PABX to VoIP or Cloud PBX in South Africa: what happens to your numbers, how long it takes, what it costs and how to avoid downtime.

Last verified 26 June 2026
By the WhichVoIP editorial team
9 min read

Keep your numbersPort your Telkom numbers across

2–3 weeksTypical end-to-end switch

Zero downtimeRun both systems in parallel

~R250 / numberTypical once-off porting fee

The short answer

How do I switch my Telkom fixed lines to VoIP?

Your new VoIP or Cloud PBX provider runs the whole switch: you assess your current Telkom setup, confirm your internet can carry calls, then sign a Letter of Authority so they can port your numbers across. Your Telkom line keeps working until the port completes, so there is no downtime. The whole process takes about two to three weeks, most of it waiting for the number port.

Steps from Telkom to live on VoIP

Business days a number port typically takes

kbps bandwidth per concurrent call

Minutes of downtime with a parallel cutover

South African Office Worker Switching From A Legacy Desk Phone To A Laptop Softphone — Switching off a Telkom line is mostly a paperwork-and-porting exercise; the technical side sits with your new provider.

What happens to your Telkom numbers?

This is the number-one worry, and the answer is reassuring: you keep your numbers.

South African number porting is a regulated process. Your geographic numbers (the ones starting with an area code such as 011, 021 or 031) move across to your new provider while your Telkom line stays live, so nothing changes for the people who call you. You sign a Letter of Authority, your new provider submits the port, and the changeover happens on a set date. Most providers either absorb the porting fee or charge a once-off amount of a few hundred Rand per number (Euphoria, for example, lists R250 per number to port in).

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Good to know: you do not need to phone Telkom to cancel first. Submitting the port automatically releases the number. For the full mechanics, timelines and reject reasons, see our number porting guide.

The switch, step by step

A typical Telkom-to-VoIP migration runs over two to three weeks. Here is what each stage looks like.

Assess your current Telkom setupCount your lines and extensions, list the numbers you must keep, note whether you have a physical PABX box, and add up your current monthly Telkom spend (line rental, calls and PABX maintenance).

Check your internet connectionVoIP runs over your internet; each concurrent call uses about 100 kbps. A 10-user office making five simultaneous calls needs only around 500 kbps, well within any business fibre line. If you are still on ADSL, move to fibre first.

Get two or three quotesPricing varies widely for the same features. Tell each provider your team size, the numbers to port and the features that matter, then compare the all-in monthly figure. Get free, no-obligation quotes from vetted providers.

Choose a provider and sign upPick the best fit for your needs and budget. Sign-up is usually done online or on a short call, and includes the Letter of Authority that authorises the number port.

Port your numbersYour provider submits the port; this is the longest stage, typically five to ten business days. Your Telkom lines keep working throughout, and your team can already make outbound calls from the mobile or desktop app.

Go live and train the teamOnce the numbers move, you are live. A short training session covers the app, desk phones, transfers and voicemail. A good provider runs both systems in parallel during the port so you never miss a call.

Cancel your Telkom servicesWith numbers ported, cancel your Telkom line rental and PABX maintenance. Check your Telkom contract for a notice period first (some business contracts need 30 to 90 days) so you do not pay for overlap longer than necessary.

What it will cost

The maths almost always favours VoIP, because you drop line rental, per-minute billing and PABX maintenance in one move. Here is an illustrative side-by-side for a 10-user office.

Line item	Telkom landline + PABX	Cloud PBX
Monthly line rental / subscription	R2,000–R5,000 (multiple lines)	R1,000–R2,000 (10 users × R100–R200)
Call charges	R1,000–R3,000 (per-minute billing)	R0–R1,000 (many plans include calls)
PABX maintenance	R500–R1,500	R0 (included)
Monthly total	R3,500–R9,500	R1,000–R3,000
Hardware (once-off)	R50,000–R150,000 (already paid)	R0–R25,000 (desk phones optional)

On these illustrative inputs, most businesses cut their monthly phone bill substantially from day one, and there is no PABX hardware left to maintain, repair or eventually replace. For a full breakdown of every cost layer, see our business phone system cost guide.

Most businesses still on a Telkom landline in 2026 are not there because it is the best option. They are there because switching feels daunting – and it is far simpler than it looks.

WhichVoIP editorial view

Technician And Business Owner Reviewing A Voip Setup On A Laptop In A South African Office — A good provider runs the old Telkom line and the new VoIP system side by side during the port, so callers never notice the switch.

Common concerns, answered

The objections that hold businesses back are mostly solved problems. Here are the four that come up most.

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“What if my internet goes down?” Good Cloud PBX providers forward calls to your team’s mobile app over 4G or 5G automatically, or to any mobile number you set. During a power cut that is actually an advantage: a VoIP system on a mobile app keeps ringing where a Telkom PABX without a generator goes dead.

“We are in a Telkom contract.” Many business contracts are month-to-month or past their initial term. If you are still in a fixed term, weigh the early-termination fee against the monthly saving; the saving often clears the fee within a couple of months.

✓

“Will call quality match a landline?” On a stable fibre line, VoIP call quality is indistinguishable from a landline and often better. The choppy-internet-call era is long gone once you have decent business bandwidth.

“It sounds complicated.” The provider handles the technical migration. Your job is to sign the Letter of Authority and brief your team. Most of the two-to-three-week timeline is simply waiting for the number port.

Questions to ask before you sign

Do you handle the entire Telkom migration, including number porting?
What happens to my calls during the porting window?
Is there a minimum contract, or can I go month-to-month?
What is included in the per-user price – are calls to SA mobiles included or extra?
Do you provide IP desk phones, or do I source my own?
What is your uptime guarantee, and do you have local SA data centres?

The bottom line

Moving off a Telkom fixed line is mostly paperwork and patience. Your numbers come with you, your old line stays live until the port completes, and your new provider carries the technical load. The switch takes two to three weeks, removes line rental and PABX maintenance from your bill, and leaves you with a system that works from any device. If you are weighing up whether now is the right time, our companion guide on why South African businesses are leaving Telkom covers the bigger picture.

Our recommendation: get two or three quotes, confirm the provider manages the full port and runs both systems in parallel, and check your Telkom notice period before you sign so the timelines line up.

Ready to switch off Telkom?

Tell us your team size, the numbers you need to keep and your budget, and compare real quotes from vetted South African VoIP and Cloud PBX providers.

Get free VoIP quotes
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Frequently asked questions

Can I keep my Telkom phone number when I switch to VoIP?

Yes. Geographic numbers (area codes like 011, 021 or 031) port across through South Africa’s regulated number-portability process. You sign a Letter of Authority and your new provider handles the port; your Telkom line stays live until it completes.

How long does it take to switch from Telkom to VoIP?

About two to three weeks end to end. The longest stage is the number port itself, typically five to ten business days, during which both systems run in parallel so you have no downtime.

Will I lose phone service during the switch?

No. Your Telkom line keeps working throughout the port, and your team can already make outbound calls from the mobile or desktop app. Calls only move to the new system once the port completes.

Do I need to cancel my Telkom line first?

No. Submitting the number port automatically releases the number from Telkom. Cancel your remaining Telkom line rental and PABX maintenance after the port, and check your contract for any notice period first.

How much does it cost to switch?

Porting a number is usually a once-off fee of a few hundred Rand (around R250 with some providers, free with others). Cloud PBX seats start from about R65 per user per month, and most businesses cut their monthly phone bill substantially after dropping Telkom line rental and PABX maintenance.

What internet do I need for VoIP?

A stable fibre line is ideal. Each concurrent call uses about 100 kbps, so even a basic business fibre line carries a full office comfortably. If you are still on ADSL or fixed wireless, upgrade to fibre before switching.

Keep reading

Why businesses are leaving Telkom
How number porting works
What a phone system costs

Sources: Porting fee and entry-seat figures verified at euphoria.co.za/pricing (26 June 2026); fixed-line decline from ICASA’s latest State of ICT report; bandwidth per concurrent call from ITU-T G.711. Cost figures are illustrative South African market ranges; number-portability process per South Africa’s regulated geographic-number-portability rules.