| ALT I ASFALT AS | 995676605 | GJERDRUM |
| ALTIBYGG BERGEN AS | 921407696 | BERGEN |
| ALT I BYGG KONGSBERG AS | 998573831 | KONGSBERG |
| ALTI-EL AS | 928736970 | KONGSBERG |
| ALTIMUR AS | 917145369 | RÅDE |
| ALT INSTALLASJON AS | 979384378 | TØNSBERG |
| ALTIPLAN AS | 914864585 | OSLO |
| ALTMULIGGUTTA TOTALREHABILITERING AS | 987972610 | OSLO |
| ALT RØRLEGGER & VAKTMESTER AS | 925597260 | HORTEN |
| ALUKO AS | 979731779 | GJERDRUM |
| Aluman Trondheim A/S | 846355022 | TRONDHEIM |
| ALUMINIUM FASADER AS | 975980596 | LARVIK |
| ALU-SERVICE AS | 911574462 | LILLESTRØM |
| ALUTEC AS | 941935400 | BJØRNAFJORDEN |
| ALVDAL BYGG AS | 977301890 | ALVDAL |
| ALVDAL GRAVESERVICE AS | 988414352 | ALVDAL |
| ALVDAL RØR AS | 918359303 | ALVDAL |
| ALVDAL TAKST AS | 893784292 | ALVDAL |
| ALVER ELEKTRO AS | 928901548 | ALVER |
| ALVER FLIS AS | 933176215 | ALVER |
| ALVERSUND MASKINSTASJON AS | 937664044 | ALVER |
| ALVØEN SERVICE AS | 918864741 | BERGEN |
| ÄLVSBYHUS NORGE AS | 975955885 | MOSS |
| A MARKUSSEN AS | 835000702 | NARVIK |
| AMBER BYGG AS | 927533146 | INDRE ØSTFOLD |
| AMBERG NORGE AS | 899162722 | BÆRUM |
| AM BYGG AS | 989557580 | ÅFJORD |
| AM BYGG & INTERIØR AS | 919295678 | LILLESTRØM |
| AMDAHL STRØM & CAPPELEN ARKITEKTER AS | 974227932 | OSLO |
| AMDAL ELEKTRO AS | 982122996 | OVERHALLA |
| ÅMDAL MASKIN AS | 990059624 | ØRSTA |
| A-MEMBRAN AS | 998823951 | OSLO |
| ÅMLI BYGG AS | 989110233 | ÅMLI |
| ÅMLI MESTERBYGG AS | 911881594 | ÅMLI |
| AM MUR OG BETONG AS | 930283886 | FREDRIKSTAD |
| AM-SERVICE AS | 921092598 | TRONDHEIM |
| AMTEDAL & HANSEN ARKITEKTKONTOR AS | 982193664 | KRISTIANSAND |
| AMUNDSEN BYGG & EIENDOM AS | 929480627 | GRIMSTAD |
| AMUNDSEN MUR & FLIS AS | 921790589 | LIER |
| AMUNDSEN RØR AS | 913018486 | BODØ |
| AMUNDSEN TAKST AS | 989658034 | ASKER |
| AMUND VOLEHAUGEN | 898811352 | NORDRE LAND |
| A. M. VIK AS | 977458412 | VANYLVEN |
| A NAGEL ALNE AS | 942265344 | VINDAFJORD |
| ANBUDSBYGG.NO DØNNESSEN | 996466485 | ULLENSAKER |
| AN BYGG AS | 997425103 | NANNESTAD |
| ANDÅS BYGG AS | 919441992 | KRISTIANSAND |
| ANDÅS RØR AS | 986085882 | KRISTIANSAND |
| ANDBERG-MOUM AS | 925342831 | OSLO |
| ANDENÆS VVS AS | 963031130 | OSLO |