| Company | Location | EASA | FAA/DAS | Scope |
| 3S Certification | USA | - | DAS | Design and certification services for one time (one off) avionics, cabin and structural upgrades. STC Project Engineering for small to large modifications including cockpit upgrades, cabin configurations, IFE, WiFi and SATCOM installations |
| AA Maintenance Services | USA | - | DAS | Aircraft modifications and cabin reconfigurations |
| ABC International | Italy | EASA | - | AP-DOA: Apply, certify and approve minor/major changes and STC for cabin interiors; Full Package Solution: Coordination of companies specialised in Cabin interiors refurbishment (carpets, leather, curtains, covers, etc.) |
| ACE | USA | - | FAA | Avionics, interiors, engines |
| ADSE | Netherlands | EASA | - | Minor changes and minor repairs to aeroplanes related to avionics, installation of avionics equipment, structure, electrical systems, hydro-mechanical systems, environmental systems, cabin interiors, galleys or other interiors equipment |
| Aernnova | Spain | EASA | - | Changes and structural repairs |
| Aero Design | USA | - | FAA | PAX cabin reconfigurations |
| Aero Excel Components | USA | - | - | Avionics packages including STC, EOs, kits, docs revisions and installation teams |
| Aero Technics | UK | EASA | - | Changes and repairs: Cabin interiors/electrical systems/structures |
| Aero-Dienst | Germany | EASA | - | Changes: Avionic and electrical components |
| Aerocon Engineering | USA | - | FAA | Airframe, propulsion, Avionics and Electronics, interiors, acoustics |
| aeroDAC | UK | EASA | - | Reconfigurations, avionics, structural |
| Aerodata | Germany | EASA | - | Changes and repairs: Avionics and related electric and structural equipment |
| AeroDEC | UK | EASA | FAA | In-house DERs, Minor/Major Repairs and Alterations, STCs, Cabin layouts, avionics, structures; A/C regulatory transitions, lease in/out consulting |
| Aerodisa | Spain | EASA | - | Cargo conversions, interior layouts, installation of new avionics and electric equipment |
| Aeromec | USA | - | FAA | DER services 23/25, structural design, analysis and tests |
| Aeroservis | Czech R. | EASA | - | Changes to aircraft related to structure and avionics |
| Aerospace DER Services | USA | - | FAA | FAA 8110-3 Approvals, Engineering Orders, Major repairs and alterations, STCs |
| Aerospace Engineering Solutions | UK | EASA | - | Part 21, Subpart J Approval for the Design & Certification of Major/Minor, Interior/Systems/Structural Changes & Repairs to all categories of aircraft |
| Aerotechnic | Germany | EASA | - | Changes: Avionics, including instruments, electrical and electronic systems installation, and related structure in cockpit and cabin |
| AES Inc. | USA | - | FAA | Avionics and electrical STCs and mods |
| AIM Aviation (Jecco) Ltd | UK | EASA | - | Changes and repairs on aircraft related to cabin interiors, structure and electrical systems |
| AIM Aviation (USA) | USA | - | FAA | Interiors reconfigurations and related structural certification |
| Air France Industries | France | EASA | - | Changes, and repairs to these changes, for cabin interiors/avionics/airframe. Minor repairs |
| Airbase Design Services | UK | EASA | - | Interior reconfigurations and mods |
| Airberlin Technik | Germany | EASA | - | Changes: Avionic systems, cabin interior, cockpit interior and related electrical systems and structure |
| Aircraft Systems & Manufacturing | USA | EASA | FAA | TBA |
| Aircraft Engine Support | USA | - | FAA | TBA |
| Aircraft Interior Resources Engineering | USA | - | FAA | TBA |
| Airline Services | UK | EASA | - | Minor changes and minor repairs to aircraft related to cabin interiors |
| Albert Muehlenberg | Germany | EASA | - | Changes: Cockpit, cabin and cargo compartment, including the related electrical and mechanical installations. |
| Amaran Group | USA | - | FAA | Alterations and repair design and approval |
| AMES | Austria | EASA | - | Changes and repairs: Structure, Electrical systems, Cabin interiors, Galleys or other interior equipment |
| ANZES | New Zealand | - | FAA | Interior reconfigurations, changes and repair design |
| Associated Air Center | USA | - | DAS | Interior reconfigurations, installation/modification of avionics |
| Atitech | Italy | EASA | - | Design and approval of minor changes and repairs |
| ATL | UK | EASA | - | Changes and repairs: Airframe structure, cabin interiors, avionics installation and electrical distribution systems |
| ATS International | France | EASA | - | Design changes: Avionics, interiors, cabin layout, external livery and related structure |
| Austrian Technik | Austria | EASA | - | STCs, Repairs |
| Avia Tecnica | UK | EASA | - | TBA |
| Avianor | Canada | - | FAA | Modifications, repairs, interiors new concept design |
| Aviation Engineering Consultants | USA | - | FAA | Major repair/alteration data approval |
| Aviation Technical Services | USA | - | FAA | Interior reconfigurations, IFE/avionics installations |
| Avionics Group Inc | USA | - | FAA | STCs development and consulting |
| Avionics Support Group, Inc. | USA | - | FAA | STCs development, PMA parts manufacturing, system installations and aircraft maintenance |
| BAE Systems Regional Aircraft | UK | EASA | - | Extensive modification/repair design capabilities under Part 21J DOA (including MRB development); Part 21G POA and UK CAA AD/1825/05 |
| B/E Aerospace (Flight Structures) | USA | - | FAA | Design, project management, integration, installation, testing and certification of reconfigurations and airframe conversions |
| BA Engineering | UK | EASA | - | Design of Supplemental Type Certificates to large aeroplanes (Airframe, avionics, cabin interiors, powerplant) |
| Bournemouth Aviation Consultants | UK | EASA | - | Changes and repairs: Cabin interiors, avionic systems, electrical systems and airframe structure |
| C&D Zodiac | USA | - | DAS | STCs, changes and repairs: Cabin interiors and equipment |
| Caledonian Airborne | UK | EASA | - | Changes: Interior equipment, avionics, electrical systems, and related structure; Repairs to products to which it holds the STC |
| Cargolux | Luxembourg | EASA | - | Changes and repairs: Avionics, structures, powerplant and systems |
| Cascade Engineering Services | USA | - | FAA | Interior reconfigurations, avionics/electrical mods, airframe structural mods, analysis, surveys |
| Ceska Letecka Servisni | Czech R. | EASA | - | Changes: Avionics, installation of avionics equipment, electrical systems, and related structure changes |
| Composites Unlimited | USA | - | FAA | STCs for galleys, closets, class dividers, stowage compartments |
| COMTECH Aviation Services | Australia | EASA | FAA | Major/Minor interior reconfigurations and modifications, STCs, in-house DERs and DAR, cabin configurations, avionics and electrical installations, galley and lavatory installations, closet and partition design and installations, technical publications |
| Cranfield Aerospace | UK | EASA | - | Changes and repairs to aircraft |
| CSA Technics | Czech R. | EASA | - | Changes: Avionics, electrical systems, cabin interiors, galleys and other interiors equipment. Repair design (secondary structure) |
| Delta Engineering | USA | - | DAS | Avionics, interior, structural design, modification and testing |
| DER Associates | USA | - | FAA | Modifications and repairs |
| DER Services | USA | - | FAA | Avionics, interiors, antennas, IFE |
| DRB Aviation Consultants | USA | - | FAA | Interior reconfigurations, avionics and structural mods |
| EAD Aerospace | France | EASA | - | Changes and structural repairs to these changes, related to Avionic, Structure and Interior |
| Emirates Engineering | Dubai, UAE | EASA | - | Minor changes and repairs |
| EMTEQ | USA | - | FAA | Structural/interior/avionics Major Modification Data Package Development, avionic systems repairs |
| Evergreen Maintenance Center | USA | - | FAA | Interior reconfigurations, structural/avionic mods |
| Finnair Tech Services | Finland | EASA | - | Changes/repairs: Cabin interiors, galleys. Minor changes and repairs to avionics, structure, environmental/hydro mechanical systems |
| Flight Line Products | USA | - | FAA | LOPA design and approvals, interior arrangement, reconfiguration support, alterations, STCs |
| FlitePartners | UK | EASA | FAA | Structures, avionics and interior STCs and mods |
| Flybe Aviation Services | UK | EASA | - | Changes and repairs: Structures, cabin interiors, cargo systems, electrical systems and installation of avionic equipment |
| FokkerServices | Netherlands | EASA | - | Large Aeroplanes |
| GAMCO | Abu Dhabi, UAE | EASA | - | Changes and repairs: Cabin interiors, galleys,, structure, avionics, electrical systems, environmental systems, hydro mechanical systems |
| GC Aviation | USA | - | FAA | Interior reconfigurations, avionics/electrical mods |
| GCT Design Organisation | Germany | EASA | - | Changes and repairs to DORNIER 328-100/-300 |
| Genesis 3 | USA | - | FAA | STCs, mods and repairs for structures, avionics/electrics and interiors |
| Southeast Aerospace Engineering | USA | - | FAA | Installation and modification services for avionics, electronics and electrical systems |
| H4 Aerospace | UK | EASA | - | Changes to metallic and composite structure, cabin interiors, furnishings, avionic, electrical and instrument systems |
| Heath Tecna (Europe) | UK | EASA | - | Design, certification and management of cabin reconfiguration programs |
| High Rely | USA | - | FAA | Total support for DO-178B and DO-254 related Avionics projects |
| Iberia | Spain | EASA | - | Changes: Cabin interiors, emergency equipment, IFE, avionics systems, electric systems, hydromechanical/environmental systems |
| International Aero Interiors | USA | EASA | FAA | Company bought by Volant |
| IPECO | UK | EASA | - | Changes and repairs: Cabin interiors |
| J&C Engineering | UK | EASA | - | Changes and repairs to aircraft |
| Jackalus Aviation, Inc. | USA | - | FAA | Interior reconfigurations, avionics/electrical, airframe structural mods/repairs |
| Jamco | USA | - | FAA | Changes and repairs to cabin interiors |
| Jamco Jade | Japan | - | FAA | Cabin modifications |
| Jet Aviation | Switzerland Germany | EASA | - | Changes and repairs: Cabin interiors. Avionic and electrical/instrument system installations |
| Kelowna Flightcraft | Canada | - | - | LOPA drawings - Transport Canada DAO |
| KLM E&M | Netherlands | EASA | - | Changes, and repairs to these changes, to cabin interiors, and airframe. Minor repairs to aeroplanes and turbine engines |
| L2 Consulting Services | USA | - | FAA | Avionics and electrical STCs - Design, integration, implementation and installations services |
| Lufthansa Technik | Germany | EASA | - | STCs |
| MAC Aviation Holdings | UK | EASA | - | Changes and repairs: Interiors, cargo systems, electrical systems, structures |
| MANN Aviation Group | UK | EASA | - | Changes and repairs: Cabin interiors, structures, avionic systems, electrical systems, mechanical systems |
| Marshall Aerospace | UK | EASA | - | Engineering Design, manufacture, maintenance, conversion, modification and logistic support for Military and Civil Aircraft. |
| Monarch | UK | EASA | - | Repairs and STC to large Transport Aircraft |
| Nayak | Germany | EASA | - | Changes and repairs: Avionics, connected with the necessary electronic and mechanical installations |
| NAT | USA | EASA | FAA | Changes: Cabin layouts, avionic systems, structures. Installations in support of cabin and avionic modifications |
| OGMA | Portugal | EASA | - | Changes and repairs: Avionics equipment, electrical systems and structures |
| Parc Aviation Engineering Services | Ireland | EASA | - | Cabin interiors changes for seating/equipment (including flammability) and avionic changes; also hold EASA CAMO approval |
| PEMCO | USA | - | FAA | Structural, avionics, electrical and interior |
| Phoenix Aviation Design Services | UK | EASA | - | Changes: Avionics, electrical systems. Installation of avionics systems |
| Quantum Avionics | USA | - | FAA | TBA |
| Regent Aerospace Corp. | USA | - | FAA | Interior reconfigurations |
| Rite Tech Aerospace | USA | - | FAA | Airframe structural repairs, interior mods, avionics/IFE installations and electrical distribution systems |
| Ruecker Aerospace | Germany | EASA | - | Changes: Cockpit, cabin interiors,cargo compartment, with necessary electrical, hydro-mechanical and mechanical installations |
| SA Design | Germany | EASA | - | Changes: Avionics, with the necessary electronic and mechanical installations, and structure |
| Sabena Technics | France (B-M) | EASA | - | Changes and repairs: Cabin interiors, avionics equipment, structure, electrical systems, environmental systems |
| SAMCO | Netherlands | EASA | - | Minor changes and minor repairs to aeroplanes |
| SAS Technical Services | Sweden | EASA | - | Changes and minor repairs: Cabin interiors, galleys. Minor changes and minor repairs to structure, environmental systems |
| Sell | Germany | EASA | - | Design changes for the installation of galleys, stowages, dividers, crew rest compartments/containers, stairhouses and lavatories |
| SR Technics | Switzerland Ireland UK | EASA | - | Supplemental Type Certificate, minor repairs and major/minor changes |
| ST Aerospace | Singapore | EASA | - | Changes and repairs: Structure, cabin interiors, galleys. Installation of avionics, electrical/mechanical systems |
| Star Aviation | USA | - | FAA | STCs for Avionics, IFE, Structural, interiors and safety |
| STC Twenty One | UK | EASA | - | TBA |
| STS Engineering Solutions | USA | - | FAA | In-house DERs (structures, electrical/avionics, systems, power plant, interiors, and composites), Minor/Major Repairs and Alterations, STCs, Technical Services (Tech Pubs, Maint. Programs, SBs, Task Cards, etc.) and on-site contract engineers |
| SWS | UK | EASA | - | Changes and repairs: Avionics, electrical systems, structures, cabin interiors, galley and other interior equipment |
| TAP M&E | Portugal | EASA | - | Changes and repairs: Avionics, structure, electrical systems, cabin interiors, galleys, powerplant, thrust reversers and nacelles. |
| TASS Inc. | USA | - | FAA | Repairs and Alterations, FAA/EASA Approvals, STCs in all engineering disciplines, Damage Tolerance, Fatigue, Maintenance Program Optimization |
| TC Inter-Informatics | Czech R. | EASA | - | Changes and repairs: Cabin interiors, structure, environmental systems, electrical systems, galleys |
| Telair | Germany Sweden | EASA | - | Changes and repairs related to cargo loading systems |
| Tenencia | UK | EASA | - | Changes and repairs: Structure, electrical, instrument, radio systems, installation of galleys or other interiors equipments |
| Timco Aerosystems | USA | - | DAS | Interior reconfigurations, flight avionics retrofits, airframe structural mods |
| TTF Aerospace | USA | - | FAA | Design/certification/manufacturing services for interiors and structural mods; electrical, water/waste and air conditioning systems mods |
| U.S. Technical | USA | - | FAA | Avionics, fuel systems, interiors |
| Volant | USA | EASA | FAA | Design, Certification, Parts Kits and Manufacturing services for interiors and structural mods; electrical, water/waste and air conditioning systems mods |
| Virgin | UK | EASA | - | Changes and repairs: Cabin interiors, avionic systems, electrical systems, airframe structure, mechanical systems and powerplant |