Below is a list of VoIP Providers that have pledged support for 3CX Phone System. They can provide you with a 3CX VoIP Provider template upon request. Once you receive the template from the VoIP provider, copy it to the following location:

C:\ProgramData\3CX\Data\Http\Templates\provider

The Provider template will now be available in the list of providers in the 3CX Management Console > "SIP Trunks" function > "Add SIP Trunk".

Note that we will not be able to support you in regards to any issues that you may experience. We recommend that you encourage the VoIP provider to undergo the formal certification procedure.