Comprehensive 3CX Phone System Upgrade Checklist: Ensuring a Smooth Transition to v20
Upgrading your 3CX phone system from v18 to v20 isn’t just a software update — it’s a major architectural shift that requires foresight, planning, and precision. From system ownership to post-upgrade configuration, each step in the process plays a critical role in ensuring business continuity and telephony reliability.
At Fidalia Networks, as a full-service 3CX Platinum Partner, we help businesses navigate these upgrades with ease — offering everything from SIP Trunks and PBX Hosting to hands-on upgrade assistance. Here’s our in-depth, field-tested checklist to guide your organization through a smooth transition to 3CX v20.
Assign a System Owner Before You Begin
The System Owner account is your key to accessing the 3CX Admin Console after the upgrade — and it must be correctly configured in advance.
- Assign a dedicated System Owner extension with a unique email address that isn’t used elsewhere in the system.
- After the upgrade, only this account will have access until additional permissions are configured.
📖 How to Assign your 3CX System Owner
Double-Check Your System and Network Requirements
Before initiating the upgrade, make sure your infrastructure aligns with 3CX’s latest requirements:
- Self-Hosted Installations need:
- At least 2 GB RAM and 2 vCPUs
- Compatibility with supported cloud providers only
- On-Premise Installations must:
- Have Split DNS configured so the 3CX FQDN resolves correctly internally and externally
Back It Up: Safeguard Your Current 3CX Setup
Never skip the backup. Seriously. This step is your lifeline if something doesn’t go as expected.
- Perform a full backup of your 3CX v18 configuration
- Store the backup off-instance in a secure location
📖 Upgrading your PBX to 3CX V20: A Quick Guide
Prepare for the Shift: Office Hours and Holidays Settings
3CX v20 introduces department-level scheduling, replacing global office hours and holidays.
- After the upgrade, you’ll need to manually configure hours and holidays for each department
- Until configured, the system will treat all calls as in-office hours
- Set call destinations for in-office, out-of-office, and break time
Executing the 3CX v20 Upgrade
When you’re ready to make the leap:
- Log into the 3CX v18 Management Console
- Navigate to the Updates section
- Select the option to upgrade to v20
- The system will update your OS to Debian 12 (for Linux deployments)
- You’ll receive an email notification when the upgrade is complete
Post-Upgrade Configuration: What Needs Your Attention
Once the upgrade is done, take these steps to re-establish full functionality:
- Log in using the System Owner credentials
- Reconfigure call routing and inbound rules — some settings may be reset or changed
- Verify user roles and call parking permissions
- Update all SBCs to versions compatible with v20
🛠️ Tip: Some users report login issues post-upgrade — typically caused by a shared System Owner email. Here’s the fix.
Architectural Changes and Known Challenges in v20
3CX v20 isn’t just a facelift — it’s a full telephony re-engineering. Key changes to plan for:
🔹 Departments Replace Groups
Queues, IVRs, and ring groups are now managed under Departments instead of Groups. Assign everything accordingly — or default them to the “General” department.
📖 3CX V20 Upgrade Checklist & FAQ
🔹 Office Hours Are Department-Specific (This is REALLY IMPORTANT)
There are no more global hours — make sure you configure each department separately or risk routing errors.
🔹 Feature Deprecations
Some features from v18 didn’t make it into the v20 launch:
- Hot desking
- Scheduled reports
If your team relies on these, consider delaying the upgrade until they’re reintroduced.
📖 3CX Forums – Feature Roadmap
🔹 Enhanced Security Measures
Security gets a major upgrade in v20:
- Passwords are now hashed
- Welcome emails no longer include passwords
- You can lock the Web Client by IP
📖 3CX V20: Telephony Re-engineered
🔹 Caller ID and User Roles
Caller ID settings and custom user roles have changed. All roles are now standardized — meaning any custom configurations from v18 will be reset.
- Reassign appropriate user access roles
- Review inbound caller ID handling, especially with non-supported providers
Fidalia Can Help You with your 3CX v20 Phone System Upgrade
Feeling Overwhelmed? Fidalia can help. Upgrading to 3CX v20 is a leap forward — we know. We’ve done a lot in the last year. Don’t get stuck with lost features or missed configurations. Fidalia is here to help.
As a Platinum 3CX Partner, we provide:
- Seamless 3CX upgrade and ongoing support
- Reliable, high-performance SIP Trunks
- Secure, scalable PBX Hosting solutions
- Ongoing system monitoring and consultation
Need help planning or executing your 3CX v20 upgrade? Let’s make it simple, smooth, and secure — together. Let’s talk.