Inspiralling compact binary systems are one of the most promising sources of gravitational waves (GWs) for the ground-based and space-based GW detectors. If they do not have spins, their evolution if fully characterized by the masses of the binary components. Very accurate evolution of the binary phase can be computed using post-Newtonian (PN) methods. We discuss how independent determination of more than two of the PN phasing coefficients can lead to consistency tests of PN theory and hence test General Relativity. Our estimates for the accuracies with which such a tests can be done are presented for various GW detector configurations such as AdvLIGO, Einstein Telescope and Laser Interferometer Space Antenna.