| PISKEY LED LIMITED | Wood products | 1940 | Total exemption (full) |
| AEG POWER SOLUTIONS LTD. | Electrical equipment | 1946 | Small company accounts |
| HENLEYS MEDICAL SUPPLIES LIMITED | Other manufacturing | 1948 | Small company accounts |
| A.S. HANDOVER LIMITED | Other manufacturing | 1949 | Total exemption (full) |
| ELSTREE PRECISION COMPANY LIMITED | Computers, electronics and optics | 1961 | Total exemption (full) |
| AXALTA POWDER COATING SYSTEMS UK LIMITED | Chemicals | 1972 | Full accounts |
| AFT FLUOROTEC LIMITED | Chemicals | 1972 | Small company accounts |
| SILVER FOX LIMITED | Electrical equipment | 1977 | Total exemption (full) |
| ELDER ENGINEERING (HERTS) LIMITED | Rubber and plastics | 1980 | Total exemption (full) |
| KANE INTERNATIONAL LIMITED | Computers, electronics and optics | 1981 | Full accounts |
| LEMSFORD METAL PRODUCTS (1982) LIMITED | Fabricated metal products | 1982 | Total exemption (full) |
| B.O.B. REALISATIONS LIMITED | Machinery and equipment | 1985 | Total exemption (full) |
| S.W. PLASTICS LIMITED | Chemicals | 1986 | Small company accounts |
| V.O.R. SERVICES LIMITED | Repair and installation of machinery | 1986 | Total exemption (full) |
| AXALTA COATING SYSTEMS UK LIMITED | Chemicals | 1988 | Full accounts |
| PRIME IMPRESSIONS LIMITED | Printing and recorded media | 1990 | Total exemption (full) |
| EVERBUILD BUILDING PRODUCTS LIMITED | Chemicals | 1994 | Small company accounts |
| HIVE INDUSTRIES LIMITED | Computers, electronics and optics | 1996 | Total exemption (full) |
| DUNCAN PRINT GROUP LIMITED | Paper and paperboard | 1996 | Small company accounts |
| MERCURY SECURITY SYSTEMS LTD | Fabricated metal products | 1997 | Total exemption (full) |
| FINGERPRINT FO+ LIMITED | Printing and recorded media | 1998 | Total exemption (full) |
| METRO COMMERCIAL PRINTING LIMITED | Printing and recorded media | 1998 | Total exemption (full) |
| SIGMA IMAGING (UK) LIMITED | Computers, electronics and optics | 2000 | Full accounts |
| SIDEL (UK) LIMITED | Machinery and equipment | 2001 | Full accounts |
| HERTS SIGNS & GRAPHICS LIMITED | Other manufacturing | 2003 | Total exemption (full) |
| AMBAR KELLY LIMITED | Fabricated metal products | 2003 | Total exemption (full) |
| GLASSON METALWORKS LIMITED | Fabricated metal products | 2003 | Total exemption (full) |
| MHP FOOD UK LIMITED | Food products | 2004 | Full accounts |
| EASY MIX CONCRETE LIMITED | Glass, ceramics, cement and stone | 2004 | Total exemption (full) |
| ROADMASTER CONCRETE MIXERS EUROPE LIMITED | Machinery and equipment | 2010 | Total exemption (full) |