Estonian legal forms explained: OÜ, AS, MTÜ, SA, TÜ
Last updated 2026-09-20
The legal form decides who is liable for a company's debts, who runs it and what it must file. Estonian names carry the form as an abbreviation or as a full word, so reading it correctly is the first step in reading a company page.
Forms of companies
OÜ, osaühing: private limited company
The most common form. The owners are shareholders (osanikud) who are liable only up to what they contributed. Its shares are not securities and are not traded on a stock exchange. A management board (juhatus) runs the company. A supervisory board is optional. Most small and medium businesses in Estonia are an OÜ, and this includes companies founded by e-residents.
AS, aktsiaselts: public limited company
Owners hold shares that can be listed on an exchange, although many AS companies are not listed. Liability of the owners is limited to their shares. An AS must have both a management board and a supervisory council (nõukogu). The form is built for larger businesses.
TÜ, täisühing: general partnership
Two or more partners run a business together. The partners are personally and jointly liable for the partnership's debts. A TÜ is a commercial partnership entered in the register.
UÜ, usaldusühing: limited partnership
A partnership with two kinds of partners. At least one general partner is personally liable without limit. The limited partners are liable only up to their contribution.
TÜH, tulundusühistu: commercial cooperative
A cooperative owned by its members that conducts business for their benefit. Consumer cooperatives and farm cooperatives use this form. The register may add a subtype such aspiiratud vastutusega tulundusühistu (limited-liability cooperative).
Forms that are not companies in the commercial sense
MTÜ, mittetulundusühing: non-profit association
An association of members that does not distribute profit to them. Sports clubs, hobby societies and many charities register as an MTÜ. It can run a business activity, but the purpose is not to pay a return to owners. Some report revenue from membership fees, grants or sales.
SA, sihtasutus: foundation
A legal person created to manage assets for a stated purpose. It has founders but no owners. Museums, hospitals and public bodies are often run as an SA.
KÜ, korteriühistu: apartment association
The association of the owners of apartments in a building. It collects money for maintenance and pays for utilities and repairs. It is a legal person with a registry code, like any other.
The form that is not published: FIE
A füüsilisest isikust ettevõtja (FIE) is a sole proprietor. It is a person doing business under their own name, not a separate legal person. The proprietor is personally liable with all their assets. The register lists FIE records, and the tax data contains FIE rows. This site excludes them completely, because a FIE's record is personal data about one individual. The exclusion covers the register data and the tax data.
Reading the abbreviation in a name
The law requires the legal form in the name of an OÜ and an AS. The name can carry it as a prefix, a suffix or a full word. All of these are real registered names:Osaühing Peedu Audit, OÜ Kuusekoda, Laiju OÜ,Aktsiaselts M ja P Nurst. The abbreviation says nothing about size. The legal form field on a company page comes from the register's own field, and does not depend on the name.
What the forms look like in the data
Among the 3,000 companies published today, the forms are distributed as follows. Forms with at least ten published companies have their own page.
| Legal form | Published companies |
|---|---|
| Private limited company (Osaühing) | 2,120 |
| Public limited company (Aktsiaselts) | 847 |
| Commercial cooperative (Tulundusühistu) | 29 |
| Limited partnership (Usaldusühing) | 2 |
| Euroopa äriühing (Societas Europaea) (Euroopa äriühing (Societas Europaea)) | 2 |
The mix reflects the selection rules: the site publishes companies with revenue and assets in a recent annual report. Non-profit associations, foundations and apartment associations often report little or no revenue in the commercial sense, so they appear less often than their number in the register suggests. The full list of forms is on thelegal forms page.
Why the form matters when checking a counterparty
- Liability. With an OÜ or AS, a creditor has a claim against the company. With a TÜ, the partners are liable too. With a FIE, the person is.
- Reporting. The financial figures on a company page come from annual reports. The forms above differ in what they file, so an absent figure does not always mean a gap in the data.
- Governance. An AS has a supervisory council, and an OÜ may not. The register shows who sits on the boards. This site does not.
- Size. Large companies exist in both the AS and the OÜ form, so the form alone says little about size. Read the revenue and the headcount.