VoIP Provider / SIP trunk Interoperability Application

Via this form you can apply to be listed as a VoIP / SIP trunk provider for 3CX Phone System. There are two Interop levels:

  • Self tested and supported –  in this case you will perform the Interop tests yourself and optionally develop a template for 3CX. You will provide this template to customers via your website. We will send you instructions how to create the template. You must develop and test this template yourself (no support provided). You must provide all support to customers – 3CX support will not be able to assist the customer in the configuration of their accounts.
  • 3CX Certified – in this case you will perform the interop tests yourself and then submit the results for testing by 3CX. 3CX will verify the results and 3CX will assist in the development of the template. This template will be available for download and will also be included in the main build of 3CX. To become certified there is a testing fee of $2495 / 1995, which covers the verification of your pre test results and development of the template. You must also provide us with a funded account. Once the interoperability tests have been confirmed, you will be listed as a supported VoIP Provider.


  • To apply to become a certified provider you must complete the Interop Test Plan and submit the results.
  • You must list 3CX as a supported platform on your website with equal importance as other platforms.
  • You must link to the 3CX website from a partners page or a configuration notes page.
  • You must commit to troubleshooting interop issues and supporting customers.


  • You can download the free edition of 3CX for testing here
  • Sign up as a 3CX partner for a free NFR here

Application to become a 3CX Interop Partner

    Contact Details

  • About Your Service

  • Support Statement & Link

  • Interop Plan Test results

  • Certified Interop Partner

  • If you wish 3CX to certify your service will required a funded test account. The account must be configured to (i) allow inbound and outbound calls to +357 numbers; (ii) allow inbound and outbound calls to +1 numbers; (iii) allow inbound and outbound calls to numbers in the home country for the VoIP Provider Service under test