Arthropods are recognised as potential mechanical and biological vectors for infectious diseases in outdoor environments. However, a comprehensive understanding of the indoor arthropod community diversity and of the role that their associated microbiota may have as disease vectors is largely unexplored. Here, we study the arthropod community and the associated microbiota diversity of twenty indoor environments, sampled over a period of twelve months from urban and suburban households by citizen scientists in the West Midlands (UK). We compare the arthropods diversity between environments and over the sampling months. We characterize the exogenous (exoskeleton) and endogenous (gut) bacterial communities associated with all specimens of arthropods actively captured using both a traditional culture-based and an unbiased metabarcoding approach. For the first time, we describe the exogenous and endogenous microbiota composition and diversity of 14 arthropod families found in indoor environments. We find that both the exogenous and the endogenous microbiota are potential carriers of human opportunistic pathogens, with potential implications for public health. We discover that many bacteria families are shared across the exogenous microbiota of arthropods, likely influenced by the bacteria present in the environment. Conversely, the endogenous microbiota composition is unique to the arthropod families, and likely genetically determined. We show that the metabarcoding unbiased approach is a superior tool to characterize the microbiota associated with each arthropod family. This study provides new insights into bacterial carriage in household arthropods as potential reservoirs of infectious disease.