The ‘party overflow’ badge will increase your access at the COP, including access to the “Blue Zone” (the Blue Zone can vary between COPs, however, it is typically home to the political and governmental parts of the COP). At previous COPs, party overflow badge holders have been able to move around the Blue Zone, attend events in country pavilions, and as space allows, observe some negotiations. The host country will likely release more information on the different zones at COP31 closer to the date.
For more information about the zones at COP31 please refer to Türkiye's COP31 website.