| JOSMAK AB | Tystberga | 0 tkr |
| J&R Capital AB | Nyköping | 0 tkr |
| JS Jonsson AB | Nyköping | 0 tkr |
| JTB i Nyköping AB | Nyköping | 0 tkr |
| Jumilla Holding AB | Nyköping | 0 tkr |
| Juniperhill AB | Habo | 0 tkr |
| JVN Holding AB | Nyköping | 0 tkr |
| K100 Invest AB | Gnesta | 0 tkr |
| K3M Bygg AB | Nyköping | 0 tkr |
| Kajkanten i Nyköping Aktiebolag | Nävekvarn | 0 tkr |
| Kantarellstigen Invest AB | Nyköping | 0 tkr |
| KA Rasmussen Förvaltning AB | Oxelösund | 0 tkr |
| Karin Boyer Förvaltning AB | Nyköping | 0 tkr |
| Karoline Haglund Förvaltning AB | Stavsjö | 0 tkr |
| Kasimina Invest AB | Nyköping | 0 tkr |
| Katta Strof AB | Oxelösund | 0 tkr |
| Kenneth Nilsson Holding AB | Nyköping | 0 tkr |
| KeyEstate Stenbrinken AB | Oxelösund | 0 tkr |
| KeyRail AB | Oxelösund | 0 tkr |
| Kialina AB | Tystberga | 0 tkr |
| KIA Maskin Aktiebolag | Nyköping | 0 tkr |
| Kickflip invest AB | Nyköping | 0 tkr |
| Kiladalen Holding AB | Nyköping | 0 tkr |
| KilaHold AB | Nyköping | 0 tkr |
| KILA INVEST AB | Nyköping | 0 tkr |
| Kinellmate Holding AB | Tystberga | 0 tkr |
| Kiropraktorhälsan B & A Holding AB | Nyköping | 0 tkr |
| Kittelö Holding AB | Nyköping | 0 tkr |
| Kjell Jansson Bygg & Projektledning AB | Nyköping | 0 tkr |
| Klava Holding AB | Nyköping | 0 tkr |
| KNP Holding AB | Nyköping | 0 tkr |
| Kolstad Bostad 1 AB | Eskilstuna | 0 tkr |
| Kolstad Bostadsförvaltning AB | Eskilstuna | 0 tkr |
| Kolstad Bostadsutveckling 1 AB | Eskilstuna | 0 tkr |
| Komprav AB | Nyköping | 0 tkr |
| Konceptura AB | Nyköping | 0 tkr |
| KONG REAL ESTATE AB | Nyköping | 0 tkr |
| Korkut Holding AB | Nyköping | 0 tkr |
| KPMO Holding AB | Nyköping | 0 tkr |
| Kripetorp Förvaltning AB | Stigtomta | 0 tkr |
| Kristina Omsorg AB | Sköldinge | 0 tkr |
| Kristin Barfknecht AB | Nyköping | 0 tkr |
| Kristoffer Wilhelmsson AB | Nyköping | 0 tkr |
| Krusell Enterprise AB | Nyköping | 0 tkr |
| Kubicon Assessment AB | Strängnäs | 0 tkr |
| KURAB Holding AB | Nyköping | 0 tkr |
| Kusttornet Holding AB | Nyköping | 0 tkr |
| Kvalitetsdryck i Nyköping AB | Nyköping | 0 tkr |
| Kvisslinge Holding AB | Nyköping | 0 tkr |
| Kv Tystberga-Eneby AB | Stockholm | 0 tkr |