ACCOUNTING, AUDITING, AND BOOKKEEPING SERVICES (SIC 8721) Establishments primarily engaged in furnishing accounting, bookkeeping, and related auditing services. These establishments may use data processing and tabulating techniques as part of providing their services. However, establishments primarily engaged in providing data processing and tabulating services are classified in Industry 7374. Establishments providing income tax return preparation services, without also furnishing accounting, auditing, or bookkeeping services, are classified in Industry 7291.