The following restrictions have been set for choosing a business name in Estonia:

• the business name must contain a reference to the legal form of the company (for example, ‘OÜ’ or ‘osaühing’ (private limited company) at the beginning or end of the name);
• the business name of a sole proprietor must include the first and last name of the proprietor;
• the business name may not contain the name of a person who is not a partner in a general partnership, who is not a partner in a limited partnership, or who is not a sole proprietor;
• the business name must be clearly distinguishable from other business names entered and booked in the business register in Estonia;
• a verbal, letter, or numerical sign protected as a trade mark in Estonia may not be used in the business name without the notarised consent of the owner of the trade mark, unless the entrepreneur operates in a field of activity for which the trade mark is not protected;
• the business name and field of activity must not conflict with each other;
• names of state or local government bodies and agencies may not be used in the business name;
• the business name of a branch of a foreign company must consist of the business name of the company and the words ‘Eesti filiaal’ (Estonian branch).

The requirement that a business name be clearly distinguishable is not limited by the specific number of letters or syllables that must be different. In some cases, merely one letter is sufficient to be different, while in another case, even three letters will not be enough. It is not just the appearance of the word that must be different but the pronunciation as well. Nor are differences in declensions, conjugations and other grammatical word endings considered differences.

A company’s business name may not be too short and should also reflect the company’s main activity (such as goods produced, services) and location of the company or shareholders/founders.