Migrating to Hosted PBX: Costs, Timelines and 12 Questions to Ask Any Provider

Once you've decided Hosted PBX is the right resilience move (covered in our companion guide on what Hosted PBX, PABX and VoIP actually mean), the next questions are practical: what does migration actually involve, what does it cost in Rands, and which 12 questions separate a genuinely good provider from an average one.

Migrating Off a Legacy PABX Without Breaking the Business

Successful migration depends almost entirely on the audit phase, not the cutover. Migrations fail because something undocumented, a lift phone, an alarm dialler, a fax line for one supplier, surfaces after the old system is decommissioned.

Project management research on IT infrastructure delivery attributes the majority of project failures to inadequate requirements gathering rather than execution. Telephony migrations follow the pattern exactly.

The typical mid-market or municipal site runs a PABX installed 10 to 15 years ago, maintained by a reseller who may no longer trade, with a dial plan in a spreadsheet nobody has opened since two IT managers ago.

Audit First: The Four Things to Document

1. Every extension and its owner, including unassigned and orphaned extensions
2. Every inbound number and its routing, main lines, direct dials, toll-free, fax
3. Every analogue device physically connected, the one that catches people
4. Every customer-facing call flow, after-hours routing, queue overflow, escalation paths

Item three routinely surfaces devices nobody in IT knew existed: a fire panel dialler, a lift emergency phone, a fax line for one supplier, a gate intercom.

Budget one to two weeks for a proper audit at a 200-seat site. It's the highest-return fortnight in the project.

What You Keep: Handsets, Numbers, Cabling

More than most buyers expect. Numbers port. Structured cabling is reused almost entirely. IP handsets from major manufacturers usually re-provision with a firmware update and configuration push.

Older digital handsets tied to a proprietary PABX generally don't survive, they speak a vendor protocol, not SIP. That's typically the largest hardware line item, so classify your fleet early.

Existing Cat5e or Cat6 cabling handles VoIP without modification. If the site has PoE switches, handset power is already solved.

Number Porting in SA: ICASA Process and Timelines

Geographic and toll-free numbers port through the ICASA-governed process, typically 10 to 20 business days depending on the losing carrier's responsiveness.

Numbers stay live throughout, the switch happens at cutover, not application. The most common rejection cause is trivial: account holder name must match the losing carrier's records exactly. A company that has changed registered name, or where the account sits under a former employee, gets rejected and restarts the clock.

The Orphans: Alarm Panels, Lift Phones, Fax, Gate Intercoms

Three options per device: retain an analogue line (appropriate for lift phones, which often carry regulatory requirements), convert via ATA gateway (presents an analogue port to the device while connecting over IP), or replace with an IP-native equivalent (cleanest long-term, highest upfront cost).

Fax deserves specific mention. Analogue fax over VoIP is unreliable regardless of provider, the protocol assumes a circuit VoIP doesn't replicate. Fax-to-email is the practical answer for almost every remaining use case.

A 90-Day Cutover Plan for a 200-Seat Site

What Hosted PBX Actually Costs (In Rands)

Hosted PBX in South Africa typically runs R100 to R250 per extension per month, but the monthly extension fee is rarely more than 60% of true first-year cost.

Very few providers publish figures. That opacity is the main reason IT managers struggle to build a business case before entering a sales process.

Per-Extension Monthly Pricing

A 200-seat site on standard extensions: approximately R30,000 to R40,000 per month before call charges.

Confirm what's included. Is call recording extra? Is the mobile app licensed separately? Are software updates included or charged as upgrades?

The Four Hidden Line Items

1. Handsets, R900 to R2,500 each. Replacing half a 200-seat fleet: R90,000 to R250,000. Usually the largest single number, often financeable over the term.
2. Onboarding and professional services, R25,000 to R80,000 for a mid-market migration. Providers quoting R0 are recovering it in the monthly rate.
3. Porting, R50 to R150 per number, sometimes waived on multi-year contracts.
4. Out-of-bundle call charges, check the per-minute mobile rate once bundles exhaust. This is where variance sits for most SMEs.

Three-Year TCO: On-Prem PABX vs Hosted

Over three years hosted typically comes out ahead, but the gap is narrower than vendors suggest, and narrows further if your existing PABX is fully depreciated.

Indicative three-year totals for 200 seats: on-premises replacement roughly R900,000 to R1.4m (hardware, licensing, installation, three years' maintenance, plus a year-five refresh looming). Hosted roughly R1.1m to R1.5m subscription, plus handsets and onboarding.

The genuine advantages are elsewhere: no capital outlay, no five-year refresh cliff, no obsolescence risk, predictable monthly cost. Buying on projected savings disappoints. Buying on resilience and eliminated refresh risk holds up.

Where Hosted PBX Does Not Save Money

Forty extensions on a fully depreciated PABX that works: hosted costs more in year one and probably year two. The case for moving is resilience or capability, not cost. Providers claiming otherwise are overselling.

Who Should Not Move to Hosted PBX

Four situations where staying put or going hybrid is correct:

1. Genuinely poor connectivity. Sites without fibre and with weak LTE will have a worse experience on VoIP than on copper. If the link can't sustain 100 kbps per concurrent call reliably, fix connectivity first.
2. Heavy analogue dependency. Sites with dozens of analogue devices, some industrial and healthcare environments, may find gateway cost and complexity outweigh the benefit.
3. Specific compliance regimes. Certain financial services and legal recording requirements carry particular retention and chain-of-custody obligations. Usually satisfiable on hosted platforms, but verify before contract.
4. A recently installed PABX. A system commissioned 18 months ago on five-year amortisation rarely justifies moving now. Plan for the refresh cycle.

UCaaS satisfaction research attributes a meaningful share of platform switching within the first two years to poor initial fit rather than product failure.

Security, POPIA and Call Recording

Hosted PBX introduces explicit POPIA obligations around call recording, data residency and access control that on-premises systems handled implicitly by keeping everything on site.

Information Regulator enforcement activity reported in its annual report to Parliament has risen steadily since POPIA commencement, with both breach notifications and enforcement notices increasing year on year.

Voice recordings are personal information under POPIA. Once they leave your premises, compliance questions become explicit, and remain your responsibility as operator regardless of who hosts the infrastructure.

Where Your Call Data Lives

Ask directly: in which country are recordings and call detail records stored? Many international platforms default to European or US data centres.

Cross-border transfer under POPIA Section 72 requires specific conditions to be met. For public-sector clients and regulated industries, local residency is frequently a hard tender requirement rather than a preference. Get it in writing before contract.

Encryption in Transit and at Rest

Signalling encrypted with TLS, media with SRTP, stored recordings encrypted at rest.

Unencrypted VoIP traffic is readable by anyone with network path access. This isn't theoretical, it's a standard penetration test finding on poorly configured deployments. Confirm both are enabled by default, not available as options.

Recording Consent Under POPIA

Four practical requirements: an announcement at call start establishing notification, documented retention periods tied to a lawful basis, restricted access with an audit trail, and automated deletion at retention expiry.

The platform should support all four. If retention is manual, it won't happen consistently.

Voice as AI Infrastructure

Your phone system is the largest untapped source of structured customer data in most SMEs, and hosted platforms make that data accessible in ways an on-premises PABX never could.

Contact centre technology research shows rapid growth in conversational AI and automated transcription deployment, with the majority of surveyed organisations either live or actively piloting.

Most hosted PBX content still reads as though it's 2018, the pitch is cost reduction and remote work. That framing is years out of date.

Practical now: automated transcription of every call, sentiment analysis across support conversations, automatic CRM logging without manual capture, routing based on caller history rather than menu selection.

Emerging: agentic systems handling routine enquiries end-to-end and escalating with full context attached, automated compliance monitoring against script and disclosure requirements.

The decision this affects is architectural. A platform with proper API access and open data export supports this trajectory. A closed platform locks you out, and you won't discover it until you try. This is why we treat voice as infrastructure for AI operations rather than a cost line, and why AI governance sits alongside the connectivity conversation, not after it.

How to Evaluate a Hosted PBX Provider: 12 Questions

Resilience

1. Which carriers do you interconnect with, and what happens during a national incident on one?
2. Does your SLA cover the last mile, or only the platform?
3. What failover options do you provide for site power and connectivity loss?
4. In how many data centres does my call routing run?

Migration

5. Do you conduct a physical audit before quoting?
6. What is your process for analogue devices, alarm panels, lift phones, fax?
7. How long does the legacy system run in parallel after cutover?
8. Who submits and manages the porting applications?

Commercial

9. What is the full first-year cost, including handsets, onboarding and porting?
10. What is the per-minute rate once bundled minutes are exhausted?

Compliance and future

11. Where are call recordings stored, and is that POPIA-compliant for my sector?
12. What API access do I have to call data and recordings?

Providers answering all twelve precisely are worth shortlisting. Providers deflecting on failover, data residency or full-year cost are telling you something useful.

Frequently Asked Questions

Can I keep my existing phone numbers?

Yes. Geographic and toll-free numbers port through the ICASA-governed process, typically taking 10 to 20 business days depending on the losing carrier. Numbers stay live throughout, the switch happens at cutover, not during the application.

How much bandwidth does a Hosted PBX need?

Budget roughly 100 kbps per concurrent voice call and 1 to 2 Mbps per concurrent video session. A 200-seat site at 20% concurrency needs about 4 Mbps for voice. Video PBX raises that materially, size for peak concurrent video, not headcount.

What happens to my alarm panel, lift phone and fax lines?

These analogue devices don't move to VoIP cleanly. They either stay on a retained analogue line, migrate to an ATA gateway, or get replaced with IP-native alternatives. Audit them before migration, they're the most common cause of cutover surprises.

Next Steps

Choosing a hosted PBX in South Africa is fundamentally a resilience decision wrapped in a telephony purchase. Features are broadly comparable across serious providers. What differs is whether the system stays reachable when the grid fails, whether migration off your legacy PABX is planned or improvised, and whether the platform supports where your business is going.

The most useful thing you can do before speaking to any provider, including us, is audit what you have. Every extension, every inbound number, every analogue device, every call flow customers depend on. That document tells you more about true cost and risk than any quote.

Innovo runs a structured resilience and migration assessment for sites between 50 and 300 seats: full inventory of your existing PABX estate, bandwidth and LAN readiness check, failover design costed against your specific load-shedding schedule, and a phased cutover plan with realistic timelines.

No demo required. The assessment is useful whether or not you move, and if the answer is that you should stay where you are for another two years, we'll tell you that.