Utilizing Space Efficiently and Improving Technologies Act of 2023 or USE IT Act of 2023 This bill requires the Office of Management and Budget (OMB) and the General Services Administration (GSA) to establish standard methodologies and identify technologies to measure federal building utilization and to use both to evaluate and consolidate public buildings and federally leased space. Federal agencies must (1) work with GSA to use sensors and other technologies in public buildings to measure occupancy, and (2) report on actual space utilization. OMB and GSA must annually ensure building utilization averages at least 60% in each public building and federally leased space over each 1-year period. The bill also requires OMB and GSA to submit a plan to Congress and the Government Accountability Office (GAO) to consolidate federal agency headquarters buildings in the National Capital region so that building utilization exceeds 60%. Occupancy agreements between federal tenants and the GSA shall stipulate annual reporting to GSA on space utilization and occupancy. Federal tenants must return office space to GSA if the occupancy of the tenant falls below a 60% space utilization rate for six months within any 1-year period. Agencies with independent leasing authorities must report space utilization and occupancy annually to Congress. The GAO shall report on agency costs and occupancy rates for public or federally leased buildings. Agencies must report certain buildings with utilization rates below 20% to the agency's inspector general for investigation.