The main difference for companies in attainment areas and nonattainment areas is the process they go through to request an increase of emissions. For large increases in emissions requiring permitting, companies in nonattainment areas must meet additional requirements, including the requirement to get offsets. This means that there will be emission reductions with the offsets, likely from a nearby area of the original pollutant source. The goal of the offsets is to move towards lower overall pollutant levels in an area.