- Design and manufacture of custom knit and crochet pieces
- Design, manufacture and installation of custom shelving solutions
- Dairy Cattle Feeding and Maintenance
- Dairy farming
- Dairy Farming of Cattle
- Dance Education
- Dance Instruction
- Data Analysis of Social Sciences and Humanities
- Data Analysis & Visualization Consulting Services
- Data Centers and Cloud Computing Solutions
- Data processing
- Data storage consultancy
- Data Storage Solutions
- Data Warehousing Solutions
- Database Backup and Recovery
- Database design and development services
- Database Management & Maintenance Consultancy
- Database Publishers
- Database publishing
- Database Services
- Database software publishing
- Day Programs for Persons with Mental Retardation and Mental Disabilities
- Dealer Services
- Debt collection agencies
- Deck Staining and Sealing
- Decking Materials Suppliers Wholesale
- Decontamination and Cleaning of Contaminated Sites
- Dehydrated Potatoes Processing
- Deli Meats and Sausage Production
- Delivery Service/ Courier Service Catering
- Delivery and installation of residential and commercial propane tanks
- Demographics Analysis and Targeting
- Demolition of Buildings
- Demolition services
- Demolition and site clearance activities
- Dental practice activities
- Department stores
- Deposit Insurance Administration
- Derivatives trading
- Dermatology
- Desalination Plant Building
- Desalination Plants
- Design and installation services for kitchens
- Design and Manufacture of Carpets
- Design and planning of arts facilities
- Design and Production of Knit & Crocheted Pullovers
- Design and Creation of Computer Media
- Design and Development of Railway Locomotives
- Design electric motors
- Design, Engineering and Installation Services Related to Radiation Equipment
- Design and engineering services for pumps and compressors
- Design and Installation of Custom Built-In Furniture
- Design and installation of projection equipment for motion pictures
- Design and Installation of Skylights
- Design and manufacture of automation systems for surface or underground mines
- Design and manufacture of custom wallpaper designs
- Design and manufacture of railway signalling systems
- Design and manufacture of spacecraft
- Design and manufacture of suspension systems for heavy motor vehicles
- Diagnostic Imaging
- Diagnostic imaging centers
- Diagnostic Imaging and Radiology Services
- Diagnostic imaging services
- Diagnostics and troubleshooting for electronic equipment
- Diesel Engine Maintenance and Repair
- Diesel Engine Repairs
- Dietary and Nutrition Counseling Services
- Dietitians and Nutritionists
- Digital Advertising
- Digital Advertising Agencies
- Digital Communications Strategies
- Digital Content Creation
- Digital Image Restoration
- Digital Imaging Services
- Digital Marketing Services
- Digital Photography Services
- Digital Printing
- Digital Printing of Computer Media
- Diners
- Dinner Cruises and Specialty Vessels
- Direct Mail/Telemarketing Sales
- Direct Response Advertising
- Direct Response Marketing Companies
- Direct selling
- Direct Selling Companies
- Directories & Guides
- Directory and database publishing
- Directory Publishers
- Disability Insurance
- Disassembling engines, transmissions, and other components for reuse or recycling
- Disaster Preparedness Training
- Disaster Recovery Planning and Implementation
- Disaster Restoration Services
- Discount Stores
- Disinfecting Services
- Dismantling and disposing hazardous materials
- Disposal of hazardous waste
- Distribution and Retail of TV & Radio Equipment
- Distribution and sale of invalid carriages
- Distribution of Film and Television Content
- Distribution of natural gas through pipelines
- Distribution Network Maintenance
- Distribution of Beer
- Distribution of Electricity
- Document preparation services
- Document Processing and Management Services
- Document Reproduction and Duplication Services
- Document Translation Services
- Documentaries
- Documentary Filmmaking
- Documentation of Dental Treatment Records
- Domestic software customization and deployment
- Domestic Violence Prevention and Intervention Services
- Door-to-door sales
- Doubling, Twisting, Winding, and Skeining
- Drain Cleaning & Jetting Services
- Drain Cleaning Services
- Drainage System Construction & Maintenance
- Drapery, Curtain & Blind Cleaning
- Drilling and Blasting Operations
- Drilling and boring contract services for mining and quarrying
- Drilling and Excavation of Crude Petroleum
- Driver’s License Tests Preparation
- Drop and upset forging
- Drop-in Childcare Services
- Dry Cargo Transport Services
- Dry Cleaning and Laundry Services
- Dry cleaning services
- Dry Van Truckload Freight Transport
- Drydock and shipyard maintenance services
- Dryer Vent Cleaning Services
- Drying
- Drywall Installation and Finishing
- Drywall Installation and Repair
- Drywall Repair and Installation
- Dual Diagnosis Treatment Centers
- DVD/Blu-ray Distributors
- Dyeing & Finishing of Textiles
- Dyeing and Finishing of Textiles Fabrics
- Design, installation, and maintenance services for fluid power equipment
- Design and manufacture of rolling stock components