Abstract Oil and gas production is inherently multiphase. A significant cost of production is directed toward accurately measuring and allocating produced hydrocarbons. The presence of gas phase in liquid flow impairs accurate measurement, introducing errors in well and field production allocation. These errors distort the reservoir engineer production information and directly affect the fiscal allocation from multiple owners. A SONAR-based system to measure the gas void fraction (GVF) next to turbine and Coriolis meters is proposed as a method to correct for gas bubbles. A test was conducted at Southwest Research Institute (SwRI) to validate this concept on realistic multiphase fluids. The SwRI test was designed to simulate separator liquid out-flow conditions and to assess the ability of GVF measurement to correct for the errors introduced by entrained gas in turbine and Coriolis meters. The data show that both the turbine and Coriolis meters over-report the volumetric flow rate in proportion to the amount of entrained gas. Using a GVF measurement provides a simple correction to the primary measurement of both meter types to within ±1% of the reference liquid flow rate for 0–8% GVF. The Coriolis meter correctly measured the mixture (liquid + gas) density within ±1% of the reference, independent of entrained gas levels. The liquid density is required to determine water-cut and in this test it was calculated by correcting the measured mixture density for GVF. Using a simple GVF correction, the liquid density was reported to within ±1% for 0–10% GVF. An accurate measure of liquid hydrocarbon volumetric flow rate and density independent of the amount of entrained gas can be achieved using turbine and Coriolis meters in conjunction with a SONAR-based GVF measurement. This capability enables improved reservoir management as well as increased separator design flexibility, reducing complexity, cost and weight.