Tests of General Relativity with black hole X-ray data

General Relativity has been extensively tested within the weak-field regime across various experiments. Recent years have seen significant progress in exploring the strong-field domain, now made possible through gravitational waves, X-ray data, and radio images of supermassive black holes like SgrAand M87. In this talk, I will discuss recent efforts to test General Relativity using black hole X-ray data, utilizing the NKBB and RELXILL_NK models. These models are employed for thermal and reflection spectra analysis from black hole accretion disks, respectively, to test the Kerr black hole hypothesis.