This study, for the first time, presents an attractive property of transversal filters: modularity. That is, for a specified Nth-order transversal filter, the N resonators could be divided into a number of modules and each module comprises arbitrary number and order of resonators, which could be implemented on a multi-mode resonator. Thus, an Nth-order filter could be synthesised by separately and independently synthesising different modules with lower orders, thus providing great flexibility, simplification and convenience in filter design. This property is realised by taking advantage of the independence between paths of transversal filters, which is guaranteed by the unique array of resonators of transversal filters. A class of transversal filter including bandpass filters and multi-band filters are synthesised, fabricated, and measured. The synthesised results, along with the good measured results, verify the validity of the modularity property of transversal filters.