Under Japanese Tax Law, Japanese companies are taxed on their worldwide income, while foreign companies are taxed only on the income earned from their activities in Japan. A Japanese company is defined as a company whose head office or main office is located in Japan (usually when the company is firstly created and registered in Japan), the nationality of its shareholders or place of central management is not relevant. Companies other than this are regarded as foreign companies.

Accounting and tax support is provided by certified public accountants and tax accountants. The role of certified public accountants is to perform audits under the Certified Public Accountant Law, while tax accountants engage in typical tax agent services such as the preparation of tax documentation and giving tax consultations under the Certified Tax Accountant Law. Additionally, both professions provide additional services such as business consulting.