This project investigates the impact of common solar PV inverters on audio frequency injection control (AFIC) signal levels. Anecdotal evidence has been reported by electricity network operators suggesting that solar inverters may be interacting with AFIC signalling. The Australian Power Quality and Reliability Centre (APQRC) employed a range of investigative techniques in order to determine the impact that inverters are having on AFIC signal levels. The process included field measurements on a commercial sized solar installation, measurements conducted within a laboratory environment and computer modelling and analysis to determine the interaction between AFIC signals and PV inverters. The computer simulation and analysis was able to replicate measurements taken in the laboratory and confirmed that the major impact occurring was due to the inverter front-end filter interacting with the high frequency AFIC signals.