The table below shows systems which the Konftel 300IP and Konftel 300IPx is tested with.
| Brand | Model | Tested | Notes |
| Alcatel-Lucent | OmniPCX Enterprise |  | |
| Avaya | Communication Manager | | » Application Note |
| Avaya | Integral Enterprise | | » Application Note |
| Avaya | IP Office* | | » Installation |
| Mitel (Aastra) | MX-ONE | | |
| Mitel (Aastra) | Ascotel i7.7 | | |
| Mitel (Aastra) | BusinessPhone | | |
| Brekeke | PBX 2.0 | | |
| Broadsoft | Broadworks | | » Validation announcement » Installation |
| Cisco | Cisco Unified Communication Manager | | » Installation |
| Digium | Asterisk | | |
| Mitel | 3300 | | |
| NEC Phillips | iS3000 v810.42, SV9100 | | » Compatibility Report |
| NEC Univerge | 3C | | Test report |
| OpenSER/OpenSIPS | | ||
| Panasonic | NCP500/1000 | | |
| SIPPY | | ||
| Unify (Siemens) | HiPath 4000 (v4.0, v5.0), OpenOffice MX | | |
| Skype Connect | | » Installation | |
| 3CX | IP Phone System | | » Installation » Test protocol |
| CommuniGate | Pro | | » Installation » Test protocol |
| Advoco NetPBX | Dialect Unified | | » Installation » Test protocol |
| Broadworks | TDC Scale | | » Installation |
| Siemens | OpenScape Office MX | | » Test protocol |
| iCentrex | iCentrex | | » Installation |
| babyTEL | | » Installation | |
| Unotelefoni | Asterisk PBX | | » Installation |
| Allworx | Allworx 48x/6x | | |
| SAMSUNG | OfficeServ7200 | | |
| Swyx | SwyxWare | | » Test details SwyxWare » Certificate |
| Vonage/Vocalocity | | ||
| AltiGen | IP-PBX** | | |
| XBlue Networks | X-50 VoIP Phone System | | |
| ShoreTel | ShoreTel 14.2 | | » Application Note » Details on ShoreTel |