As part of our interest in organic-inorganic metallate complexes, we had prepared a novel non-centrosymmetric chlorobismuthate (III) compound with the chemical formula (C6H7NCl)3 [BiCl6]·H2O, by slow evaporation method at room temperature. It was characterized by single crystal X-ray diffraction (SCXRD), X-ray powder diffraction (PXRD), spectroscopic measurements, thermal study, Hirshfeld surface analysis, DFT investigation, and antimicrobial activity. A preliminary SCXRD structural analysis revealed that the compound crystallizes in the Orthorhombic system (P212121 space group) with the following unit cell parameters a = 7.3432 (1) Å, b = 13.8257 (2) Å and c = 28.2140 (5) Å with Z = 4 and V = 2864.42 (8) Å3. The examination of the structure shows that its atomic arrangement can be described as inorganic [BiCl6]3- units isolated from each other by the organic cations and the co-crystallized water molecules. The cohesion between these entities is performed via the NH⋯Cl, NH⋯O, CH⋯O, CH⋯Cl, and OH⋯Cl hydrogen bonding interactions between the 4-dichloroanilinium cations, the [BiCl6]3- anions and water molecules forming a 3D network. The Hirshfeld surface calculation was conducted to investigate: intermolecular interactions, associated 2D fingerprint plots, and enrichment ratio, indicating the relative contribution of these interactions in the crystal structure quantitatively. Thermal analysis reveals the decomposition of the compound at 180 °C. The quantum mechanical calculations such as geometry optimization, vibrational frequencies, simulated UV–Visible spectrum, FMOs analysis were made together with the experimental studies. Furthermore, the new synthesized compound was screened for its antibacterial activity. Results revealed that it has the most effective activity against all the tested bacteria compared to the amine alone and to the BiOCl.