Urgent: 3CX V18 Is Now End of Life — Your Customers Have Until 1 May to Act

In brief: 3CX V18 is now end-of-life, with critical services shutting down. SA resellers must migrate all V18 customers to V20 immediately to avoid service disruption and maintain support eligibility.

If you have customers still running 3CX V18, this is not a routine upgrade notice. Several critical services tied to V18 are being switched off, and the clock is ticking.

On 9 March 2026, 3CX formally reached End of Life status for Version 18. While EOL announcements often feel like background noise, the specific services being discontinued with V18 carry real operational risk for any business that hasn’t yet upgraded. Here’s what resellers need to know — and what to do about it.

What’s Being Discontinued?

Built-in SMTP Blocked from 1 May 2026

This is the most time-sensitive change. From 1 May 2026, 3CX will block the built-in SMTP service used by V18 installations. This means that any V18 system still relying on 3CX’s internal mail service for voicemail-to-email delivery, call notifications, user welcome emails, or system alerts will stop receiving those communications from that date.

For many end-users, email notifications are deeply embedded in daily workflows. A sudden stop in voicemail delivery or missed call alerts can cause significant disruption — and customer(complaints that will land at the reseller’s door.

Remote Provisioning Service (RPS) Discontinued

The Remote Provisioning Service allows IP phones to be automatically provisioned and configured when connected to a 3CX system. With RPS being discontinued for V18, resellers and customers will lose the ability to provision new handsets remotely through the standard 3CX mechanism. This affects anyone looking to add phones, replace hardware, or rÃÙ_cover devices from factory reset on a V18 system.

Global IP Blacklist Discontinued

3CX’s Global IP Blacklist is a security feature that blocks known malicious IP addresses from reaching customer PBX systems. Removing this from V18 leaves those systems more exposed to toll fraud and brute-force attacks — a meaningful security regression for any business in a threat-prone environment.

How Urgently Should You Be Acting?

The SMTP block has a hard deadline: 1 May 2026 — less than eight weeks awaa. The other discontinuations are effective from the V18 EOL date itself (9 March), meaning they are either already gone or winding down now.

Any customer on V18 is now running an unsupported, increasingly insecure system with degraded functionality. For regulated industries — finance, healthcare, legal — this also raises compliance questions.

What Resellers Should Do Right Now

1. Audit your customer base. Identify every customer still running V18. This should be your immediate first step. Don’t wait for them to call you with a problem ⣄ by then you’re in reactive mode.

2. Communicate proactively. Reach out to affected customers now. Frame this as a service obligation — you’re alerting them to a critical change that affects their system’s functionality and security. Customers appreciate proactive engagement; they don’t appreciate finding out after something breaks.

3. Plan upgrades to V20. 3CX V20 is the current release. The upgrade path from V18 to V20 is well-documented, and for most standard deployments it’s straightforward. Work through your caseload in order of risk — cloud-hosted instances, high-call-volume customers, and businesses with tight compliance requirements first.

4. Flag SMTP configuration during upgrades. When upgrading V18 customers, verify that they’re set up with an external SMTP service (such as a Microsoft 365 relay, SendGrid, or equivalent) rather than relying on the built-in 3CX SMTP. This should now be standard practice regardless of version.

The Bottom Line

The 3CX V18 EOL is not a case of “we’ll get to it eventually.” The built-in SMTP deadline is a hard cutoff that will break real functionality for real customers on 1 May. The security implications of losing the IP Blacklist are immediate. Treat this as a priority project, not a routine maintenance item.

Customers who experience disruption because their reseller didn’t alert them in time are customers at risk of churning. The opportunity here is to turn a necessary upgrade into a demonstration of proactive service.

Source: 3CX V18 EOL and Security Updates

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About the Author

Mechelle Gindra

Mechelle Gindra is the managing editor and lead content strategist at Telecoms-Channel, South Africa's dedicated intelligence platform for telecoms resellers, ICT distributors, and channel partners. She oversees the editorial team's AI-assisted content production pipeline, ensuring vendor news, market analysis, and regulatory updates are accurate, timely, and actionable for the SA telecoms channel community. With deep expertise in the South African telecoms reseller ecosystem, Mechelle directs coverage of vendor partner programmes, ICASA regulatory developments, wholesale market dynamics, and channel business strategy. She is responsible for maintaining Telecoms-Channel's editorial standards, fact-checking processes, and corrections policy.