We present a comprehensive study of resonance formation in electron collisions with thiophene. Detailed calculations have been performed using the ab initio R-matrix method. Absolute differential cross sections for electron impact excitation up to 18 eV and for two scattering angles, 90 and 135 degrees, have been measured. Agreement between the calculated and measured experimental cross sections is very good. Three shape resonances previously described, two of pi* character and one sigma*, as well as a number of resonances of core-excited or mixed character are identified and characterized in the calculations. The measured cross sections provide experimental confirmation for a number of the core-excited resonances. The link between these resonances and prior DEA experiments is discussed.