ALICE T0 serves as a start, trigger and luminosity detector for ALICE. The accurate interaction time (START) serves as the reference signal for the Time-of-Flight detector that is used for particle identification. T0 supplies five different trigger signals to the Central Trigger Processor. The most important of these is the T0 vertex providing prompt and accurate confirmation of the location of the primary interaction point along the beam axis within the set boundaries. The detector is also used for online luminosity monitoring providing fast feedback to the accelerator team.