Installing 3CX Phone System
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Installing 3CX Phone System

Installing 3CX Phone System for Windows

On this topic

Installing 3CX Phone System for Windows

System Requirements

Supported Operating Systems

Supported Hardware and VM Platforms

Firewall & Network Considerations

No NAT Firewall Configuration

NAT Mode Firewall Configuration

Other requirements

FQDN for the 3CX Phone System machine

Preparing the Windows Host Machine for Installation

Installing 3CX Phone System

Running the 3CX Phone System Configuration Wizard

Upgrading From a Previous Version of 3CX Phone System

Step 1: Backup your configuration & Uninstall the old version

Step 2: Install 3CX Phone System v14

Step 3: Restore your configuration

Activating your License

System Prompts Language

See Also

System Requirements

Supported Operating Systems

3CX Phone System v14 is supported on the following operating systems:

  • Windows 7 Professional (x64)
  • Windows 7 Ultimate (x64)
  • Windows 7 Enterprise (x64)
  • Windows 8 Pro (x64)
  • Windows 8 Enterprise (x64)
  • Windows 8.1 Pro (x64)
  • Windows 8.1 Enterprise (x64)
  • Windows 10 Pro (x64)
  • Windows 10 Enterprise (x64)
  • Windows 2008 R2 Foundation (x64 only)
  • Windows 2008 R2 Standard (x64 only)
  • Windows 2008 R2 Enterprise (x64 only)
  • Windows 2008 R2 Datacenter (x64 only)
  • Windows 2012 Foundation (max. 15 presence connections on IIS installations)
  • Windows 2012 Standard
  • Windows 2012 Datacenter
  • Windows 2012 R2 Essentials (max. 25 presence connections on IIS installations)
  • Windows 2012 R2 Standard
  • Windows 2012 R2 Datacenter

Installations on Microsoft Windows Server Core versions are not supported. ​It should be noted that on client operating systems Windows 7, 8, 8.1 and 10, Abyss will be used as the web server, whereas on Windows Server, IIS will be used.

Supported Hardware and VM Platforms

3CX Phone System is extensively tested to be run as a VM which eliminates the cost of separate hardware and adds high availability solutions based on the hypervisor infrastructure. Supported hypervisor platforms are:

  • VMware ESX 5.X and above.
  • Microsoft HyperV 2008 R2 and above. See our Hyper-V Page for the specific settings for running 3CX Phone System.

Avoid using 3CX Phone System on converted VMs (P2V) because a converted virtual machine might have timing issues, which causes the guest operating system not to sync with the timer of the hypervisor.

System performance depends on five key factors:

  • How many simultaneous calls will the system handle.
  • How many people will simultaneously connect to the presence server.
  • If call recording is used.
  • If VoIP Providers are used.
  • If call routing built is mainly around queues and IVRs.

Based on these factors the hardware can vary from Intel i3 CPUs with 4Gb of RAM up to a multi socket/core system. General guidelines can be found online in these articles:

Firewall & Network Considerations

3CX Phone System allows two network topology deployment options:

  • No NAT - no NAT is performed from public to a private network. The Network card’s IP address would be a public IP.
  • Behind NAT - a firewall / router is between the internet and the PBX which performs network address translation. The Network card’s IP address would be a private IP.

No NAT Firewall Configuration

In case of No NAT, it is sufficient to use the built In “Windows Firewall” to secure the machine. You do not need to do anything as the 3CX Phone System installation will open all the required ports automatically.

NAT Mode Firewall Configuration

If 3CX Phone System is installed behind a NAT device, ports need to be forwarded. See the following guides detailing the requirements:

Other requirements

  • Latest version of Firefox, Google Chrome or Internet Explorer.
  • Microsoft .NET Framework version 4.5 or higher.
  • You will need to have a good basic understanding of Windows Networking.
  • A constant internet connection to on port 443.
  • On demand connection to* on port 80 for 3CX Management Console downloads and additional information.

FQDN for the 3CX Phone System machine

An FQDN is required for the following reasons:

  • Easy access to the 3CX Management Console.
  • For easy management of IP phones and services in case of an IP change.
  • To setup HTTPS for the console.
  • To securely provision IP phones using HTTPS.

The FQDN must resolve on your LAN to the machine on which 3CX Phone System is installed, and from the internet it must resolve to your Public IP. You can choose to have a separate FQDN for internal and external connections or a single FQDN for both using Split DNS. Find more information on how to Create FQDN using Split DNS.

Preparing the Windows Host Machine for Installation

Tasks that MUST be completed before installing 3CX Phone System:

  • Assign a static internal IP address to the host machine’s network adapter.
  • Install all available Windows updates & Service packs before installing 3CX Phone System. The reboot after installing Windows updates may reveal additional updates. Pay particular attention to install all updates for Microsoft .Net before running the 3CX Phone System installation.
  • Antivirus Software should not scan the following directories to avoid complications and write access delays:
  • C:\Program Files\3CX PhoneSystem\*
  • C:\ProgramData\3CX\*

In case the 3CX Phone System host machine has multiple network adapters:

  • Disable unused network interfaces / Wi-Fi adapters.
  • One active network interface MUST have a default gateway configured. It is illegal and wrong to have multiple network interfaces all with default gateways configured.
  • Prioritize the primary network interface (the one with the default gateway configured) to the first position from: “Control Panel” > Network and Internet > Network Connections. Press the Alt key to reveal the File menu and click on Advanced” > “Advanced Settings”. The “Adapter and Bindings” tab > “Connections” section will show your interfaces. Ensure that the network card with the default gateway is at the top.


  • Do not install VPN software on your 3CX Server
  • Ensure that all power saving options for your System and Network adapters are disabled (Set the system to High Performance).
  • Do not install TeamViewer VPN Option on the host machine.
  • Disable Bluetooth adapters if it is a client PC.
  • 3CX Phone System must not be installed on a host which is a DNS or DHCP server, has MS SharePoint or Exchange services installed.

Installing 3CX Phone System

  1. Download the latest version of 3CX Phone System.
  2. Double-click on the setup file. Read the system requirements. Click “Next”.
  3. Read our configuration recommendations. Click “Next”.
  4. You will be asked to review and accept the license agreement.
  5. Select the installation folder path, 3CX Phone System will need a minimum of 10GB free hard disk space. You will need to reserve additional space to store voicemail files, recordings & voice prompts. Choose the location to install and then click “Next”.

  1. Select the Phone System Installation mode, select Standard Installation (Single Instance). Click “Next”.

  1. Select whether 3CX Phone System is about to be installed on a machine which is directly on the internet (no NAT configured - where the result of “ipconfig” command will result a public ip) or whether the server is behind a NAT device (NAT configured - where the result of “ipconfig” command will result a local ip). Select the appropriate option and click “Next”. 

  1. You will now need to enter your Static Public IP Address, type it in and click “Next”. Furthermore check that the installation has detected the correct default network card.   
  2. Enter your Server Administrator Email Address that will receive notifications. Click “Next”.

  1. Specify the FQDN of the machine on which you will be installing 3CX Phone System:
  • Single FQDN, for example: “”. The FQDN must resolve on your LAN to the machine on which 3CX Phone System is installed, and from the internet it must resolve to your Public IP. If the domain is not dedicated to the PBX and subdomains are used for other services, such as, then you will need to use Split DNS on your router/DNS Server. Alternatively you can dedicate a cheap domain to your PBX. More information on how to Create FQDN using Split DNS.
  • External FQDN and Local FQDN, for example & pbx.interobit.local. If you do not want to dedicate a domain or use Split DNS, you can select to use a separate external /local FQDN. The external FQDN will be used for devices connecting from outside the LAN. Not recommended, because this complicates provisioning and slows connecting of the clients (as it can not rely on DNS but instead has to check both URLS). If you do not have the ability to create a local FQDN for the LAN , then you can enter the IP Address in the local FQDN field.
  • No FQDN - If you do not want to connect to the PBX from outside the LAN, you can specify a local IP. IP phones or clients can not be used outside the LAN. Abyss must be used as the web server.
  1. Fill in the details of your SMTP server that will be used to send out email notifications. Click “Next”.
  2. Now specify the Management Console username and password. Make sure to use a strong password to prevent unauthorised access to your PBX. Usernames and passwords are both case sensitive. Click “Next”.
  3. 3CX Phone System requires a web server, “Microsoft IIS” or a bundled web server “Abyss”.
  • If installing on a Server OS then IIS is the best solution.
  • If you checked the option “I do not have an FQDN”, Abyss will be automatically selected.
  • Abyss will be automatically selected if 3CX is installed on a client desktop OS (Windows 7, 8, 8.1, 10).
  • If ports 80 or 443 are already in use by another service on the same host, then you must select Abyss because you can configure different ports for HTTP and HTTPS. The IIS option in 3CX does not allow you to edit web ports and are hardcoded to 80 and 443.
  1. If Abyss is selected, you will have the ability to change the http and https ports that the web server will listen on. Accept the defaults (http: 5000, https: 5001) or type in your own.

  1. If you have an SSL Certificate for the FQDN or domain that you entered, select “Import an SSL Certificate”. Otherwise you can choose the option to generate a self-signed certificate.

  1. The above image shows the Import Trusted SSL Certificate. Here you should import a “pfx” file and enter the certificate password in the Password field. If in Step 15 you chose “I do not have an SSL Certificate - generate one for me”, you will be asked for a company name and a certificate password so the certificate can be generated on the fly.

  1. Click “Install” to start the installation of 3CX Phone System. Setup will now copy all files and install the necessary Windows services.

Running the 3CX Phone System Configuration Wizard

The 3CX Phone System configuration wizard will walk you through a number of essential tasks that you need to do in order to get your system up and running.

  1. After installation is complete, double click the 3CX Management Console icon from your desktop.
  2. Enter the username and password that you specified during setup, select the language you would like to use and click the “Login” button. Note that the username and password are both case sensitive. The "Configuration Wizard" will be displayed which will walk you through the initial configuration step by step.  

  1. Choose the number of digits that extension numbers should have. This cannot be altered later. Click “Next”.

  1. Select your country and time zone settings and click “Next”.

  1. Configure the Operator Extension by entering first name, last name and email address. This is  the default destination for inbound calls. Confirm that the VoiceMail Extension number is appropriate for your installation and click “Next”.

  1. Specify the countries or regions to which calls can be made. Calls to countries which are not selected will be blocked. This feature reduces the risk of VoIP toll fraud. Select the countries you would like to allow and click “Finish”.

You have now completed the initial configuration of 3CX Phone System. You will be redirected to the quick 3CX Phone System Management Console. The Quick Start page will show you the next steps you will need to take.

Upgrading From a Previous Version of 3CX Phone System

If you are running an old version of 3CX Phone System (9, 10) you must upgrade to v11 SP 4a, and then to v12 SP 6.1 before following this upgrade procedure. If you are using 3CX Phone System v12 SP 6.1 or v12.5 you can go to v14 directly. 

If upgrading from 12.5 ask your users to upgrade their 3CXPhone clients to the latest version to ensure in place updating to v14. See our guides with instructions for installing and upgrading 3CXPhone Clients for Windows, Android, iOS and Mac.

Step 1: Backup your configuration & Uninstall the old version

  1. Make a backup of your current configuration using the 3CX Backup and restore tool.
  2. Tick the options to include in your backup, then choose where to save your backup. Warning: Do not choose to store the backup inside any of the 3CX Phone System installation folders as these folders are removed during the uninstall process.
  3. Uninstall the current version from the Windows Control Panel > Programs and Features.

Step 2: Install 3CX Phone System v14

  1. Download 3CX Phone System Version 14
  2. Proceed with the installation as documented above.
  3. Complete the 3CX Configuration Wizard.

Step 3: Restore your configuration

  1. Go to the 3CX Management Console


  1. Go to the “Backup and Restore” node. Click on the “Location” button. Select the location where your backups are stored (Local Disk or FTP) and configure the “Select folder path” to the folder where your backup is located. Press OK. After this you should see the backup from the location together with the backup details and size.  


  1. Select the backup you want to restore and click “Restore” button from the toolbar.
  2. The management console will log out and the restore process will start. When the restore is complete, an email will be sent to the Administrator email configured during the setup. This means that the restore completed, was successful and you can login to the 3CX Management console. 

Activating your License

Without a license, 3CX Phone System will work for up to 2 simultaneous calls. If you require more, then you will need to activate a license. There are two ways to access the activation page in order to activate a license, you can either click on the Activate License link in the Quick Start page or directly from the “Settings” > “Activate License” node, from within your 3CX Management Console.

Enter your License Key, Company, Contact Name, E-mail, Telephone, Country and the name of your Reseller (The company who you bought 3CX from) and click on “Activate” to activate your license.  

  • This information will be sent to our license key server to activate your license key.
  • To be entitled to your first year of free upgrade insurance, your details must be correct. These details are reviewed by 3CX and if they are not correct the upgrade insurance will not be activated.

If you license your 3CX Phone System and then reinstall on a new machine, change hardware, or the local network topology changes (for example the local MAC address changes), you will need to re-activate your licenses.

Note: Packets between the 3CX Phone System server and should not be filtered or inspected. If you run DPI (Deep Packet Inspection), license key activations will be rejected.

System Prompts Language

3CX Phone System ships with a US English prompt set by default. Prompts are recorded voice files that are played by the system to callers and users of the system. For example, when a user picks up their voice mail, the system prompts will instruct the user what buttons to press in order to hear or delete voice messages. To change the system prompts to a different language:

  1. Go to “Updates” > “System prompt sets” node, select the prompt set you wish to use and click on “Download Selected”. The prompt set will be downloaded to your machine.
    Note: Download only the prompt set that you need.
  2. Go to “Settings” > “System prompts” > “Manage Prompt sets” at the top of the screen.
  3. Select the prompt set that you have downloaded and click on “Set As Current Prompt Set”. The system will now use this new prompt set.

See Also



You might also be interested in:

Ask a Question

Please only post questions in regards to the document you are currently reading.
Technical support or pre sales questions must be posted via the support or sales channels and such comments will be deleted. Thank you for understanding

Leave a Reply

  1. Leilani Giltinag

    My computer is a Windows 7 Home Premium (x64). Will the 3CX be compatible with my OS?

    July 6, 2015 at 4:26 am Reply
    • Charalambos Eleftheriou

      Hi Leilani, 3CX Phone System requires Windows pro or ultimate desktop OS.

      July 6, 2015 at 9:30 am
  2. Windows Server 2012 R2 Essentials is shown as a supported operating system but the instructions say not to install 3CX on a system that hosts DNS. DNS is required on Essentials. Are there any issues running DNS and 3CX on Essentials? I installed it fine on my system and haven’t had any issues but it’s only been a week.

    July 7, 2015 at 5:26 pm Reply
    • Charalambos Eleftheriou

      @Brian, It is simply a recommendation. If you are not experiencing any issues then all is well.

      July 8, 2015 at 11:49 am
  3. ali

    hello sir can i get remote voicemail access from 3cx phone system i have also install
    3cx phone system windows ubuntu but not open software so kindly help me

    July 20, 2015 at 3:50 am Reply
    • Charalambos Eleftheriou

      @Ali, thanks for your question. You can access your voicemail by dialling in to an IVR, while the IVR is playing enter the Voicemail number (999 by default). Then enter your extension when promoted then your voice mail password. Sorry Ubuntu is not supported.

      July 20, 2015 at 10:00 am
  4. Aaron

    What do you do when migrating to a new server and you don’t have the license information? I have the license key, but the previous installer did not document anything else.

    July 31, 2015 at 4:31 am Reply
    • Charalambos Eleftheriou

      @Aaron, thank for the question. All the required information will be in the activate license section of your current installation. If you have already removed the phone system then you can contact our sales department who will be able to help you retrieve the information.

      July 31, 2015 at 7:29 am
  5. Michael Bijzet

    “If upgrading from 12.5 ask your users to upgrade their 3CXPhone clients to the latest version to ensure in place updating to v14”
    this mean the client has to be on 12.5 sp2 or on v14 before updating the server?

    September 28, 2015 at 5:02 pm Reply
    • Charalambos Eleftheriou

      @Michael, thanks for the question. When you are upgrading make sure that the 3CXPhone clients are on the latest version with the latest patches applied then when you go to v14 the process is automatic and no reprovisioning is required.

      September 28, 2015 at 5:24 pm
  6. Paul Daly

    Can the SSL certificate be changed from a self signed one to one issued by a certified authority after installing V14 or do I have to uninstall and re install V14 again?

    October 13, 2015 at 1:29 am Reply
    • Charalambos Eleftheriou

      @Paul thanks for the question. To install your SSL you will need to take backup, remove 3CX then re-install, choosing to import your SSL during the installation. Configure using the config wizard then restore your backup.

      October 13, 2015 at 2:15 pm

    i’m have the 3cx11 backup.
    the backup not compatible for 3cx14?

    October 16, 2015 at 4:39 pm Reply
    • Charalambos Eleftheriou

      Hi, a backup from v11 is not compatible with v14.

      October 16, 2015 at 6:38 pm
  8. Markus

    Hi, is it possible to change the FQDN mode of the system after install. We first only did IP address and would like to migrate now to split FQDN. We didn’t found a way yet to do this. The FQDN entry in the management tool is greyed out and read only.

    October 27, 2015 at 10:09 pm Reply
    • Charalambos Eleftheriou

      @Markus, thanks for the question. In order to change the FQDN you will have to take a backup, remove 3CX Phone System, Re-install with the required FQDN, configure using the config wizard and restore your backup.

      October 27, 2015 at 10:32 pm
  9. Martin Kendrick

    I have two 3CX platforms both running on IIS Win2008 64bit. One site upgraded to V14sp1 from 12.5 with no issues. The other site upgraded and works fine with the exception of some menu items that worked fine before – all “updates” menu items respond with 3CX interface cannot connect to web server, the phones item reports cannot get manufacturers information. Most other items all work and PBX works in respect to calls and presence is distributed fine. From PBX I can browse 3CX web site and any other web site with no issues, DNS test is successful. All these worked fine on 12.5 on this machine before update. I have reverted the platform and updated 3 times now with same results every time. Any thoughts I am at a total loss to see what is wrong. With Wireshark I do not see any request leave the server when I select check fro updates.

    October 31, 2015 at 12:05 pm Reply
    • Charalambos Eleftheriou

      @Martin, thanks for the question. Are you using 2008 Server R2?. As this is the only tested and supported Windows 2008 server platform for v14.

      November 3, 2015 at 4:09 pm
  10. Alan Licht

    i made mistakes on my FQDN and need to change. How can i do this. Do i need to reinstall v14? Will it overwrite all my configuration of phones? help. Thanks

    November 1, 2015 at 1:25 am Reply
    • Charalambos Eleftheriou

      @Alan, thanks for the question. In order to change the FQDN, you must take a backup, uninstall, re-install using the correct FQDN then configure using the config wizard and restore your backup.

      November 3, 2015 at 4:13 pm
  11. Mauro

    Hi, I am using the free version of 3cx phone sistem. I see now there is an update with SP1 but I cannot download it from the console cause I have no maintenance and the maintenance is not available for the free version. I want to ask: i I dowload the new setup of the free verzion of 3CX with the SP1, have I to perform “Backup, Uninstall Old, Install New and Restore” or may I install directly the new version without any problem to get the SP1 update?

    November 9, 2015 at 7:20 pm Reply
    • Charalambos Eleftheriou

      @Mauro, thanks for the question. Yes you can perform a backup, uninstall old version, install and configure v14 with sp1 then restore your backup.

      November 9, 2015 at 8:31 pm
    • @Mauro – We are working on this.
      for now you have to take a backup, uninstall and install and restore.

      November 10, 2015 at 10:26 am
  12. Spring

    If i have single domain ex: can i choose External FQDN and Local FQDN during setup? and type both External and Internal?

    January 5, 2016 at 5:26 am Reply
    • Charalambos Eleftheriou

      @Spring, if you have an external FQDN that resolves both externally and internally then use the first option, single FQDN with Split DNS no need to enter it both externally and internally.

      January 5, 2016 at 10:12 am
    • Spring

      Thanks you for your answer. i am still not yet clear if i have domain that resolve internally with my internal DNS and add record in my DNS hosting to resolve externally so do i need to use split dns?

      January 6, 2016 at 4:20 am
    • Charalambos Eleftheriou

      @Spring, from what I understand you have the same domain name internally and externally. In which case no extra configuration is needed and you can still use the single FQDN option.

      January 6, 2016 at 10:14 am
    • Spring

      Thanks you for your answer. so could you tell me when split dns will be used?

      January 8, 2016 at 4:14 am
    • Charalambos Eleftheriou

      @Spring, thanks for the reply. Best practices state that an internal domain name should be different from an external domain name. For example, external domain is ‘’, internally the domain could be called ‘mydomain.local’, when setting up my Windows AD for instance. When this is the case then, when using the single FQDN option, the external FQDN for example, ‘’ will need to be added as a forward lookup up zone in the internal DNS infrastructure in order for it to be resolvable internally.

      January 8, 2016 at 9:54 am
  13. Cesar Landazuri

    Hello can I change the FQDN later after the installation? How?.

    January 14, 2016 at 12:38 am Reply
    • Charalambos Eleftheriou

      @Cesar, thanks for the question. Once installed it can not be changed. To change the FQDN you will have to take a backup, uninstall your 3CX Phone System, reinstall with the new FQDN then configure using the config wizard and restore your backup.

      January 14, 2016 at 9:41 am
  14. Spring

    How can i change my 3cx server timezone after completed the installation?

    January 14, 2016 at 4:16 am Reply
    • Charalambos Eleftheriou

      @Spring, thanks for the question. The time zone is set during the configuration using the config wizard. Once installed it can not be changed.

      January 14, 2016 at 9:38 am
    • Spring

      Ok thanks for your information.

      January 14, 2016 at 11:10 am
  15. Grant Williams

    I’m doing an install and I’m at the spot of entering info for the Operator extension and it won’t accept any email address I set. it keeps telling me that the email address is either empty or invalid…what can I do to resolve this?

    April 14, 2016 at 8:15 pm Reply
    • Charalambos Eleftheriou

      @Grant, Please make sure the email address is typed in lower case and if coping and pasting the address, that there are no spaces either at the beginning or the end of the email address.

      April 14, 2016 at 8:26 pm
    • Grant Williams

      @Charalambos email address is typed in fine, tried 50 different addresses…not using copy/paste for that…it’s not accepting anything I put in there…

      April 14, 2016 at 10:48 pm
    • Charalambos Eleftheriou

      @Grant, If 3CX is being installed on a Sever OS 2012 for example, open the Windows Server manager then locate >> Local Server >> then from the IE Enhanced Security Configuration section >> set both the options of IE to off then try again.

      April 15, 2016 at 4:46 pm
  16. saad

    I am migrating from 12 to v14, we currently have 2 digit extensions. after installing the v14 we would like to go to 3 digit extension. can i configure v14 as 3 digit, then restore from 12, export my extensions and change the digits in csv and import extensions. Will this work or I will need to create my extensions from scratch

    June 10, 2016 at 4:28 pm Reply
    • Charalambos Eleftheriou

      @Saad, to change extension digit lengths will require configuration from the beginning, you can not restore a backup from a system that had 2 digit extensions to a system that has 3 digit extensions.

      June 10, 2016 at 5:39 pm
  17. Victor Manuel Rozo Sànchez

    How can I change the language from English to Spanish. My PBX is in English I need it in Spanish.

    July 9, 2016 at 5:30 am Reply