Automatic Data Processing Inc

ADP sells payroll processing and HR software to businesses of all sizes—from small businesses to large enterprises—across 140 countries. Its core products handle payroll, tax compliance, benefits administration, talent management, and retirement services. It also runs a Professional Employer Organization (PEO) business, where it co-employs clients' workers and manages HR functions on their behalf. ADP earns revenue through software subscription fees, per-employee-per-month service fees, and float income on client funds held before disbursement. It serves over 1.1 million clients and processes payroll for more than 42 million workers.