Most business owners who've been putting off switching to VoIP say the same thing afterwards: they wish they'd done it sooner. Not because the technology is exciting — it isn't, really — but because the whole thing turned out to be far less complicated than they expected.

There's no major installation. No technician who needs to spend a day running cables. No shutting the office down while you migrate. If you have a decent internet connection and a phone, you're most of the way there already.

Here's how to do it, step by step.

Step 1: Check your internet connection

VoIP runs on your internet connection, so that's where you start.

Bandwidth requirements are very low. Each active call uses roughly 100kbps, so a standard 10Mbps fibre line can comfortably handle 50+ simultaneous calls with room to spare. For most SMEs, what you already have is fine.

A few things worth checking:

Speed isn't everything — stability matters more. A 100Mbps line with packet loss or high jitter will give you worse call quality than a 20Mbps line that's rock-solid. If your team regularly complains about laggy video calls or choppy audio in Microsoft Teams, VoIP will expose the same issues. A quick network quality test (not just a speed test) will tell you whether you have a problem worth fixing before you switch.

LTE and wireless connections work, but with caveats. If your office runs on LTE as a primary or backup connection, VoIP will still function, but call quality is more variable than on fibre. For a reception desk or high-volume sales team, a wired fibre connection is worth the investment. For remote workers on mobile, VoIP apps over LTE are generally fine for day-to-day calls.

Your router matters. Consumer-grade routers can struggle to prioritise voice traffic over large file downloads or video streams. If you're serious about call quality, ask your provider about QoS (Quality of Service) settings. This tells the router to always prioritise voice packets. Most business-grade routers support it, and it's often the difference between "good enough" and "excellent."

Step 2: Choose your VoIP provider

This decision matters more than any piece of hardware you buy.

The right provider will handle your number porting, provision your extensions, walk you through the setup, and actually answer the phone when something goes wrong. The wrong one will leave you debugging SIP settings alone at 8pm because the support queue is in another time zone.

What to look for in a South African context:

An ICASA licence is non-negotiable. It's what gives a provider the legal right to offer voice services in South Africa, and it's what protects your business if something goes wrong. Check the ICASA website or ask any provider to confirm their licence number directly.

Local support is worth more than you might think. International VoIP platforms can be very cheap, but when you have a call routing issue on a Monday morning and your customers are ringing out, you want support that's reachable, knows the local network, and is available during SA business hours.

Month-to-month pricing removes the risk. Avoid any provider pushing 24-month contracts. If the service isn't working for you, you should be able to leave. Full stop.

At Othos, we're ICASA licensed, Cape Town-based, and run on month-to-month billing. See pricing →

Step 3: Choose your hardware

Here's where a lot of businesses overthink things.

You have three options: dedicated VoIP desk phones, softphone apps on laptops, or a mobile app on your team's phones. Most businesses end up using a mix of all three.

Dedicated IP phones are the right choice for reception desks, call centres, or anyone who spends most of their day on the phone. They're purpose-built for voice calls — good speaker quality, physical hold and transfer buttons, and they don't compete with a browser and twenty open tabs for your attention. Brands like Yealink and Grandstream offer reliable hardware at reasonable prices.

Softphones (apps that run on your laptop) work well for team members who take calls regularly but aren't glued to a handset all day. Add a decent headset — Jabra and Plantronics are the workhorses here — and you're done. No desk phone needed.

The mobile app is often overlooked, but it's powerful in a South African context. Your staff take and make calls using the business number on their personal phones. Customers see your business number on caller ID. During load shedding, when your office goes dark, calls automatically route to wherever your team has mobile data. The phone system keeps running. Your customers still get through.

One thing you don't need: a traditional PBX box sitting in your server room. With cloud VoIP, the "PBX" is software running in a data centre. Nothing to install on-premise, nothing to maintain, and no single piece of hardware that takes your entire phone system down if it fails.

Step 4: Port your existing number

You don't have to change your business number. Number porting lets you bring your existing number — whether it's a Telkom landline, a Vodacom number, or an 087 — across to your new VoIP provider.

In South Africa, porting is regulated by ICASA and managed through the Number Portability Company. The process isn't complicated, but it takes time: typically 5 to 10 business days from submission to completion, depending on your current provider.

A few things to know before you start:

Your number must be active and in good standing. If it's been suspended or has an outstanding balance, sort that out first.

You'll sign a porting declaration authorising the transfer. Your new provider handles the submission on your behalf.

You don't go dark during the process. Most porting happens seamlessly — your number keeps working on the old system until the cutover moment, then switches over. There's typically a brief window (minutes, not hours) during which calls may not connect.

If you're taking a new number instead of porting, provisioning is immediate. Your provider assigns it, you configure it, and you're live the same day.

Step 5: Configure your system

With numbers in place and hardware sorted, the next step is setting up how the system actually behaves.

Most businesses start with three things:

Auto-attendant (IVR): This is the "press 1 for sales, press 2 for support" menu. You record the greeting yourself, set up the menu options, and tell the system where to route each selection. A well-set-up IVR makes even a 3-person business sound professional and ensures calls reach the right person. It takes about 20 minutes to configure if you know what you want.

Extensions and ring groups: Each staff member gets their own extension. Ring groups let you point a single number at multiple people simultaneously — useful for a sales team where you want any available person to pick up, rather than having it go to one inbox. You configure this through your provider's dashboard; no technical knowledge required.

Call routing and business hours: You can tell the system to behave differently outside office hours — send calls to voicemail, route to an after-hours message, or forward to a mobile. Set those rules up here, and test them before going live.

Step 6: Test before you go live

Don't skip this step.

Call your own number from an external phone and walk through every option in your IVR. Make sure calls route where you expect them to. Test your hold music. Check that voicemail works and that the recording arrives in your inbox.

Put two handsets on the system and make internal calls between extensions. Check that transfers work. Try a call from the mobile app on a mobile data connection, not just your office Wi-Fi.

Catch problems now rather than when a client calls and gets stuck in a broken menu.

Common mistakes to avoid

Skipping the network quality check. A fast internet connection doesn't guarantee good call quality. Test your jitter and packet loss before signing up — most providers will help you do this.

Buying hardware before confirming compatibility. Not all IP phones work with all VoIP platforms. Check with your provider before purchasing.

Underestimating how long porting takes. If you have a hard go-live date, start the porting process well in advance. Ten business days is the optimistic end — give yourself two to three weeks.

Not setting up call recording from day one. It's optional, but you'll want it the first time a client dispute comes up and you need a record of what was said.

Rather let someone else handle it?

The steps above aren't complex — but that doesn't mean you have to do them yourself. At Othos, we handle the full setup: number porting, hardware provisioning, IVR configuration, extension setup, and testing. You don't need to know anything about SIP or codecs or dial plans. That's our job.

If you're ready to make the switch — or just want to know what it would cost for your team size — start here.

Get started with Othos →

See VoIP plans and pricing →

Related reading:
VoIP for Small Business in South Africa: Everything You Need to Know
What Is Cloud PBX? A Plain-English Guide for SA Businesses

Questions? Get in touch →