3CX SIP Trunk Providers - USA
These SIP Trunk providers in the USA have been tested and certified by 3CX. We strongly recommend using a preferred or supported SIP Trunk service provider. The 3CX team makes sure that all templates from listed SIP Trunk Providers are updated and tested with every release ensuring no issues arise for our users.
Registration-based trunks with no IP fixation remain the preferred option in a hosted environment. This is because in certain cases the Public IP of your Hosted by 3CX can change unexpectedly. Although this is not a regular occurrence, if this happens, you will temporarily lose the ability to make and receive calls via your IP-based trunks.
Read our guide on how to configure a SIP Trunk / VoIP Provider. This covers the generic steps required to configure a trunk with 3CX. Some providers may need special configuration requirements. Before choosing a SIP Trunk provider in your region, carefully check our listing for these special requirements and be sure to follow any extra configuration guides added.
Preferred Providers
Preferred Providers are compatible with all 3CX installation modes. They are thoroughly tested with each build of 3CX and require no manual configuration. You can simply plug and play your PBX with a SIP Trunk of your choice.
Capabilities
SMS Support | No |
Anonymous Calling | No |
Clip No Screening Support | No |
Fax Support | Yes - T38 Bypass |
SIP TLS Support | No |
IPV6 Ready | No |
Online Sign-Up & Portal | Yes |
Important Configuration Notes
Enter the main trunk number in international format (e.g. 17778811960).
You can only present numbers associated with your account as Outbound Caller ID.
Be sure to follow the configuration guide.
Capabilities
SMS Support | Yes |
Anonymous Calling | No |
Clip No Screening Support | Yes |
Fax Support | Yes - T38 Bypass |
SIP TLS Support | Yes |
IPV6 Ready | No |
Online Sign-Up & Portal | Yes |
Important Configuration Notes
Enter the main trunk number as E164.
Be sure to follow the configuration guide.
Supported Providers
Supported Providers are tested against 3CX Hosted and on-premise installations. Compatible with all 3CX installation modes.
Capabilities
SMS Support | Yes |
Anonymous Calling | Yes |
Clip No Screening Support | Yes |
Fax Support | No |
SIP TLS Support | No |
IPV6 Ready | No |
Online Sign-Up & Portal | Yes |
Important Configuration Notes
Enter the main trunk number as E164.
Dialling must be in either 11 digit format (17778811960)0 or full +E164 format (+17778811960).
Be sure to follow the configuration guide.
Capabilities
SMS Support | No |
Anonymous Calling | Yes |
Clip No Screening Support | Yes |
Fax Support | No |
SIP TLS Support | No |
IPV6 Ready | No |
Online Sign-Up & Portal | No/Yes |
Important Configuration Notes
Enter the main trunk number as E164.
For calls within the US, you must enter the number in the 11 digit format.
For international calls enter only the country code without the "+" and without 011.
Be sure to follow the configuration guide.
Capabilities
SMS Support | No |
Anonymous Calling | No |
Clip No Screening Support | No |
Fax Support | Yes - T38 Bypass |
SIP TLS Support | No |
IPV6 Ready | No |
Online Sign-Up & Portal | Yes |
Important Configuration Notes
Enter the main trunk number in national format (e.g. 7778811960).
Be sure to follow the configuration guide.
Supported (Dedicated Servers Only)
Supported Providers (Dedicated Servers only) are tested against 3CX Hosted and on-premise installations. Not compatible with 3CX FREE/SMB. Configuration may require a few extra steps.
Capabilities
SMS Support | No |
Anonymous Calling | Yes |
Clip No Screening Support | Yes |
Fax Support | Yes |
SIP TLS Support | No |
IPV6 Ready | No |
Online Sign-Up & Portal | Yes/Yes |
Important Configuration Notes
Enter the main trunk number as E164.
Be sure to follow the configuration guide.
Capabilities
SMS Support | Yes |
Anonymous Calling | Yes |
Clip No Screening Support | Yes |
Fax Support | Yes - T38 Bypass |
SIP TLS Support | No |
IPV6 Ready | No |
Online Sign-Up & Portal | Yes |
Important Configuration Notes
Enter the main trunk number as E164.
Be sure to follow the configuration guide.
Capabilities
SMS Support | No |
Anonymous Calling | Yes |
Clip No Screening Support | Yes |
Fax Support | Yes - T38 Upscale |
SIP TLS Support | No |
IPV6 Ready | Yes |
Online Sign-Up & Portal | Yes |
Important Configuration Notes
Enter the main trunk number in the national format (e.g. 7778811960).
CenturyLink supports SRTP. Enable it from the trunk settings in the Management Console "Options > Advanced > SRTP Mode".
Capabilities
SMS Support | No |
Anonymous Calling | Yes |
Clip No Screening Support | Yes |
Fax Support | No |
SIP TLS Support | No |
IPV6 Ready | No |
Online Sign-Up & Portal | No |
Important Configuration Notes
Enter the main trunk number in the national format (e.g. 7778811960).
Under the “General” tab, enter the primary SIP Server IP.
Under the “Options” tab in the “Alternative Proxy” field add the secondary IP.
To use “Clip No Screening” request the functionality from Convergia.
By default, only numbers associated with your account can be presented as outbound caller ID.
A static public IP is required.
Capabilities
SMS Support | Yes |
Anonymous Calling | Yes |
Clip No Screening Support | Yes |
Fax Support | Yes - T38 Bypass |
SIP TLS Support | No |
IPV6 Ready | No |
Online Sign-Up & Portal | Yes |
Important Configuration Notes
Enter the main trunk number as E164.
Be sure to follow the configuration guide.
Capabilities
SMS Support | No |
Anonymous Calling | Yes |
Clip No Screening Support | No |
Fax Support | No |
SIP TLS Support | No |
IPV6 Ready | No |
Online Sign-Up & Portal | No |
Important Configuration Notes
Enter the main trunk number as E164.
Outbound rules: numbers must be dialed only in E164 format. Disable the "E164 Processing" from the MC > Settings.