Accounting, bookkeeping, and tax service providers. These professionals specialize in green, sustainable, and socially-responsible businesses. These businesses may be eligible for special tax incentives put forth by state and federal governments to promote certain causes such as environmental protection. At the same time these businesses, especial non-profit organizations, may be subject to certain compliance and reporting requirements. Qualified accountants can help navigate the legislations, accounting and tax codes. Many accounting professionals also provide business planning and advisory services.