| Ytreland AS | Veavågen | 1983 |
| Ytreland Mur & Bygg AS | Tønsberg | 2024 |
| Ytrevoll Holding AS | Årdal I Ryfylke | 2023 |
| Ytter Holding AS | Farsund | 2022 |
| Ytterbøe Invest AS | Ulefoss | 1998 |
| Ytterdahl AS | Farsund | 2022 |
| Ytterli Invest AS | Isfjorden | 2019 |
| Ytterli Maskin AS | Isfjorden | 2022 |
| Yttersia Eiendomsutvikling AS | Lakselv | 2015 |
| Yttersia Maskin AS | Stokmarknes | 2024 |
| Yttervik Holding AS | Fauske | 2015 |
| Ytteråsen Avløpsanlegg Utbygging SA | Stjørdal | 2025 |
| Yttri Entreprenør AS | Åmot | 2026 |
| Yukira AS | Tromsdalen | 2024 |
| Yussupov Og Vaupsas Forretningsprosjekt AS | Oslo | 2016 |
| Yutwest Nuf | Ee-13513 Haabersti Linnaosa Tallinn | 2019 |
| Yri Sand A/S | Loen | 1988 |
| Z Best AS | Tønsberg | 2013 |
| Z Bygg & Maling AS | Stavanger | 2026 |
| Z Bygg AS | Frogner | 2020 |
| Z&Z Investgroup AS | Jessheim | 2025 |
| Z-Clix AS | Kristiansand S | 2022 |
| Z. P. U. H. Malgo Grzegorz Piotr Lukasiuk | 21-512 Zalesie | 2006 |
| Z. W Kantor Da | Risøyhamn | 2004 |
| Z.P.U.H Damal Danuta Lukasiuk Nuf | Drammen | 2007 |
| Z.P.U.H. Rafal Kaldon | Pl-85-218 Bydgoszcz | 2020 |
| Z.R. Impianti S.R.L | 41043 Formigine (Mo) | 2011 |
| Zac Bygg AS | Hjellestad | 2017 |
| Zachodnie Centrum Inwestycyjne SP. Z.O.O. Nuf | 60-774 Poznan | 2022 |
| Zagreb-Montaza D.O.O. Za Gradnju Gospodarskih Objekata Nuf | Hr-22000 Grad Sibenik | 2024 |
| Zak Bygg AS | Jar | 2004 |
| Zaki Ac AS | Nesttun | 2026 |
| Zakis Bygg AS | Hafslundsøy | 2023 |
| Zaklad Ogolnobudowlany Jerzy Niedzielin | 84-300 Lebork | 2008 |
| Zaklad Ogolnobudowlany Marek Suchoszek | 42-674 Zbroslawice | 2008 |
| Zaklad Ogolnobudowlany Witold Tadeusz Szmyd | 11-400 Ketrzyn | 2006 |
| Zaklad Ogonobudowlany | 62-402 Ostrowite | 2011 |
| Zaklad Produkcyjno-Uslugowo- Handlowy-Milczuk Wieslaw | 22-400 Zamose Lubelskie | 2003 |
| Zaklad Remontowo Budowlany Majocha Sylwester | Åmot | 2008 |
| Zaklad Remontowo-Buddwlany MGR Inl Jaroslaw Wirkowski | 16-300 Auguston | 2005 |
| Zaklad Remontowo-Budowlany Slawomir Szymczak Nuf | 87-700 Aleksandrow Kujawski | 2014 |
| Zaklad Remontowo-Budowlany Tomasz Radon | Pl-33-100 Tarnow | 2016 |
| Zaklad Slawomir Grzesik | Pl-34-120 Andrychow | 2014 |
| Zaklad Stolarski Eugeniusz Sosnowski | Lunde | 2007 |
| Zaklad Storlarsko-Budowlany Tadeus Wichrowski | 82-300 Elblag | 2006 |
| Zaklad Uskug Budowlanych | 48-300 Nysa | 2008 |
| Zaklad Uslug Remontowo - Budowlanych I Transportowych Adam Idziak | 78-449 Borne Sulinowo | 2014 |
| Zaklad Uslugowy Maxi-Rem Grzegorz Marchewka | Pl-41-807 Zabrze | 2012 |
| Zaklad Uslugowy Monter Radoslaw Ciba | Moss | 2005 |
| Zaklad Uslugowy Posadzkarstwo Pawel Gajewski | 63-069 Dabrowa | 2008 |
| Zampell | Dk-7260 Søndre-Omme | 2006 |
| Zampich Estrichbau | Sortland | 2009 |
| Zan Bygg AS | Flateby | 2021 |
| Zap Elektro AS | Oslo | 2026 |
| Zauner Anlagentechnik GmbH Nuf | At-4702 Wallern An Der Trattnach | 2024 |
| Zauner Romania S.R.L - Nuf | Oslo | 2025 |
| Zaza Timber Construction Nuf | Lv-3002 Cenu Pagasts Jelgavas Novad | 2021 |
| Zbigniew Chyra | 42-700 Lubliniec | 2007 |
| Zbigniew Klim Plim | 77-310 Debrzyno | 2007 |
| Zbigniew Mirkowski | 80-206 Gdansk | 2007 |
| Zbigniew Nalepa Repairs - Building Services Nuf | Ås | 2021 |
| Zbigniew Stanislaw Was | 80 169 Gdansk | 2010 |
| Zbigniew Stolc | 84-240 Reda | 2007 |
| Zbygg Service AS | Oslo | 2021 |
| Zdzislaw Zblewski | 77-330 Czarne | 2007 |
| Ze Bra Holding AS | Moss | 2018 |
| Ze Bra Vei AS | Moss | 1989 |
| Zeab AS | Skiptvet | 2024 |
| Zedmontage GmbH & Ladenbau KG | 14482 Potsdam | 2007 |
| Zeefax Limited | Gb-London W6 0Rr | 2016 |
| Zeiner Bolig Håndverk AS | Nøtterøy | 1988 |
| Zek Performance AS | Oslo | 2023 |
| Zelina AS | Tromsø | 2021 |
| Zeller Bäderbau GmbH | De-10623 Berlin | 2014 |
| Zeller Bäderbau GmbH - at | At-6410 Telfs | 2017 |
| Zemgales Tehnologiskais Centrs | Lv-3017 Jelgavas Novads | 2011 |
| Zen Bygg AS | Heimdal | 2018 |
| Zen Eiendom AS | Horten | 2023 |
| Zenith Bygg AS | Vikhammer | 2013 |
| Zenith Bygg Consult AS | Lørenskog | 2012 |
| Zenith Property AS | Lørenskog | 2014 |
| Zentrum Bygg Nuf | Ottestad | 2021 |
| Zeri Electric AB Nuf | Se-433 38 Partille | 2023 |
| Zetterstrøm & Aarkvisla AS | Hokksund | 1994 |
| Zewaray AS | Isdalstø | 2022 |
| Zeynpol Ans | Notodden | 2006 |
| Zi Holding AS | Askim | 2016 |
| Ziarekbygg AS | Oslo | 2018 |
| Zibi S.C. | 66-400 Gorzow Wlkp | 2008 |
| Zichtbaarstroom | Kaupanger | 2026 |
| Zida AS | Skien | 2026 |
| Zidar Norway | Rs-19300 Negotin | 2015 |
| Zigaras Antanas | 06329 Vilnius | 2010 |
| Zigis Bygg AS | Nærsnes | 2016 |
| Zijdemans Consult AS | Hokksund | 2017 |
| Zik Service AS | Oslo | 2023 |
| Ziki Bygg AS | Oslo | 2019 |
| Zikzac Service AS | Lillestrøm | 2019 |
| Zimmerei Graichen Nuf | De-09249 Taura | 2023 |
| Zimmerei Harald Lange | 17498 Neunkirchen | 2011 |