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Search›Companies›O3 Inseneribüroo OÜ
12321790ActivePrivate limited companyEE101632351 · VAT-registered

O3 Inseneribüroo OÜ

Saare maakond, Saaremaa vald, Kuressaare linn, Tolli tn 7·EMTAK 71121 — Constructional engineering-technical designing and consulting·13+ years
Andmed · ···
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Overview

e-Business Register · 23 h ago
Registry code
e-Business Register
Legal form
Private limited company
Registered
30.07.2012e-Business Register
Address
Tolli tn 7, Kuressaare linn, Saaremaa vald, 93813 Saare maakondADS · e-Business Register
E-mail address
info@o3.eee-Business Register
Telephone
+372 53870338· Telia Eesti ASe-Business Register · TTJA NBA
Principal activity
EMTAK 71121 - Constructional engineering-technical designing and consultinge-Business Register · ETCB
VAT number
ETCB · VAT-registered
Share capital
2500,00 €e-Business Register
Estonia's public business register
HomeViewsIndustriesBlogSourcesAbout

Public registry of Estonian companies — every fact traceable to a source and a date. Free and ad-free for everyone.

Nimistu MTÜ
Address: Parda tn 8, 10151 Tallinn, Estonia
E-mail: info@nimistu.ee

Browse

  • Home
  • Views
  • Industries
  • Recent registrations

Data

  • 72 sources
  • Database
  • Extensions
  • MCP

Organisation

  • About
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© 2026 Nimistu MTÜ. License CC-BY-SA 4.0 · details
Data · 8 sourcese-Business Register · 8 min agoMTAMTR
e-Business Register ↗

Registered 30. juuli 2012, primary activity: Constructional engineering-technical designing and consulting. Main place of business in Kuressaare linn, Saaremaa vald, Saare maakond.

Revenue 2026 (I kv)
167 446 €
▼ 5% vs 2025 I kv
As of 10.04.2026 (MTA)
Employees
16
2026 (MTA)
Taxes paid
158 647 €
State + labour taxes · 2026 (I kv)
Tax debt
0 €
As of 27.06.2026 (MTA)
Revenue 2026 (I kv)
167k €
▼ 5% vs 2025 I kv
As of 10.04.2026 (MTA)
Employees
16
2026 (MTA)
Taxes paid
159k €
State + labour taxes · 2026 (I kv)
Tax debt
€0
As of 27.06.2026 (MTA)

Officers (2)

e-Business Register · 23 h ago
MV
Mats Viisileht
Born 1990 · 36 y · board member since 05.05.2025
Board member
MH
Mihkel Hiielaid
Born 1993 · 32 y · board member since 05.05.2025
Board member

Founders

e-Business Register · 23 h ago
MT
Mikk Tasa
Born 1987 · 39 y · founder since 30.07.2012
Founder · 3k €

Shareholders

e-Business Register · 23 h ago
OT
O3 Technology OÜLEGAL PERSON
Legal person · 14062364 · shareholder since 01.09.2023
Shareholder 100% · 3k €

Beneficial owners (2)

e-Business Register · 23 h ago
MV
Mats Viisileht
Born 1990 · 36 y · ultimate beneficial owner since 30.01.2026
Ultimate beneficial owner
MH
Mihkel Hiielaid
Born 1993 · 32 y · ultimate beneficial owner since 30.01.2026
Ultimate beneficial owner

Annual reports (6)

e-Business Register · annual reports · 1 päeva tagasi
Revenue 2024
683k €
↗ +14.2% vs 2023
State taxes 2025
445k €
↗ +33.8% vs 2024
Employees 2024
9
↘ -35.7% vs 2023
YearRevenueProfit

Taxes, revenue and employees

Estonian Tax and Customs Board · 10.04.2026 as of
200k €100k €0

Licences (4)

MTR · 22 h tagasi
Active licences
4
Other4
Oldest · Newest
2013→2025
Oldest licenceTEL002170 · 12.07.2013
Newest licenceTTV000053 · 21.04.2025
Active4 / 4
TTV000053
Valveseadmestiku projekteerimine, paigaldamine ja hooldamine
Majandustegevusteade
From21.04.2025
UntilOpen-ended
Valid

Tech stack

Tehnoloogiad
Mobile carrier
+372 53870338Telia Eesti AS

History

last 2 years · MTA + ÄR + MTR + Procurements
2026
30.01.2026OfficerLisati tegelikuks kasusaajaks2×expand ›hide ⌃
  • Mihkel Hiielaid
  • Mats Viisileht
2025
30.06.2025ReportEsitati 2024. aasta aruanne— Käive 683 447 €
05.05.2025OfficerAstus juhatusse

Connected companies

Same-person ties · e-Business Register

O3 Inseneribüroo OÜ is connected to 8 other companies through 3 people who hold a role here and elsewhere. The strongest tie runs through Mats Viisileht (3 companies).

Total connections
8
via 3 people
Connecting people
3
Active here
Distinct roles
3
Board member · Ultimate beneficial owner
Strongest tie
Mats
3 companies
Via personMats Viisileht
Equity
Assets
Employees
2024683 447 €−2905 €52k €218k €930.06.2025
2023598 660 €22 493 €55k €137k €1416.04.2024
2022561 799 €685 €32k €115k €1529.06.2023
2021401 292 €−134 465 €32k €110k €1305.05.2022
2020546 784 €25 945 €166k €235k €1311.06.2021
2019529 335 €21 665 €178k €236k €1417.04.2020
Original files in PDF – the full register on e-Business Register.View reports on e-Business Register
20222023202420252026
YearRevenue (a)State taxesTaxes on workforceEmployees (Q4)
2026I Q167 446 €96 960 €61 687 €16
2025673 999 €444 818 €298 791 €15
2024666 800 €332 478 €220 379 €18
2023613 324 €344 554 €240 912 €14
2022559 966 €307 114 €214 878 €14
Quarterly breakdown
YearQ1Q2Q3Q4
Revenue 2026167k €–––
State taxes 202697k €–––
Taxes on workforce 202662k €–––
Employees 202616–––
Revenue 2025177k €172k €178k €147k €
State taxes 2025111k €129k €110k €94k €
Taxes on workforce 202574k €87k €74k €64k €
Employees 202518181615
Revenue 2024153k €142k €184k €187k €
State taxes 202457k €104k €104k €68k €
Taxes on workforce 202440k €76k €58k €46k €
Employees 202415142018
Revenue 2023155k €154k €164k €141k €
State taxes 202388k €83k €94k €79k €
Taxes on workforce 202362k €58k €66k €55k €
Employees 202315161414
Revenue 2022142k €164k €102k €151k €
State taxes 202277k €83k €71k €77k €
Taxes on workforce 202254k €56k €55k €50k €
Employees 202218151514
FPR000414
Projekteerimine
Majandustegevusteade
From08.02.2024
UntilOpen-ended
Valid
EEP002617
Projekteerimine
Majandustegevusteade
From03.04.2020
UntilOpen-ended
Valid
TEL002170
Elektritööd
Majandustegevusteade
From12.07.2013
UntilOpen-ended
Valid
2×
expand ›
hide ⌃
  • Mihkel Hiielaid
  • Mats Viisileht
05.05.2025FilingMuutmiskanne2×expand ›hide ⌃
  • Ä 10171940 / 17 · Olek: Jõustunud
  • Kanne nr 16 · kanne
21.04.2025LicenceUus MTR tegevusluba— Majandustegevusteade · TTV000053
3
Mihkel Hiielaid3
Mikk Tasa2
MV
Mats Viisileht
board member, ultimate beneficial owner
3 other companies›
CompanyRoleReg. code
MAVI OÜ
Shareholder 100%Board memberUltimate beneficial ownerFounder
16925384
O3 Energy OÜ
Board member
14291372
O3 Technology OÜ
Board member
14062364
MH
Mihkel Hiielaid
board member, ultimate beneficial owner
3 other companies›
CompanyRoleReg. code
Hiimek OÜ
Board memberUltimate beneficial ownerFounderShareholder 100%
16232043
O3 Energy OÜ
Board member
MT
Mikk Tasa
founder
2 other companies›
CompanyRoleReg. code
O3 Energy OÜ
Ultimate beneficial owner
14291372
O3 Technology OÜ
Ultimate beneficial ownerShareholder 25%Founder
14291372
O3 Technology OÜ
Board member
14062364
14062364