Start with the question your search must answer
A company register records legal events for the entities within its jurisdiction, whereas a business directory may simply collect commercial contact details. Before searching, decide whether you need evidence of incorporation, a current address, filed accounts or permission to conduct a regulated activity. These questions may lead to different authorities even when the same business name appears in each service.
Recognise the boundaries of each database
Companies House offers a corporate record search in the United Kingdom; DATA INPI provides French enterprise information; European e-Justice explains the participating national systems. Use these starting points to identify the responsible registrar, then record the entity number and source date. A matching entry establishes what that register discloses, rather than certifying every claim made by the business.