Turn this list into pipeline.
Oil & Gas Companies in Southampton: 35 Active Firms (2026)
Oil and gas companies around Southampton provide exploration, production, storage and specialist services across the regional energy economy.
Buying tends to sit with asset operators, port-linked logistics teams, refinery and marine engineering managers, and procurement functions that need technical work delivered without carrying permanent specialist capacity. Around Southampton, the relevant suppliers are usually B2B, project-led and close to energy infrastructure rather than consumer retail. Typical engagements appear to cover inspection, maintenance, equipment supply, storage support, field engineering and logistics, with contract size shaped by asset risk, outage timing and customer assurance requirements. The buyer is likely to value availability, safety documentation and sector familiarity as much as price.
Read more
Southampton has 35 actively trading oil and gas companies in this list, making it a compact local cohort rather than a broad regional cluster. The reported employment footprint is 343 people, which points to a market built around specialist service teams, technical subcontractors and owner-managed suppliers rather than large operating workforces. That shape is consistent with a port and marine-adjacent energy economy: relatively few firms, but activity that can serve offshore, industrial and logistics customers beyond the city itself. The scale profile also suggests that revenue concentration matters more than firm count when assessing competitive weight.
Hydrocarbon-linked work around Southampton sits inside a permissioned operating context, even where the company itself is not an asset owner. Formal obligations vary by activity: storage, marine logistics, inspection, maintenance and engineering support each carry different expectations around safety cases, environmental controls, insurance and customer audit. Contracting structures also matter. Smaller suppliers often enter through framework agreements, project subcontracting or outage-led work packages, where the immediate commercial gatekeeper may be an operator, port customer or engineering prime rather than the final energy user. That tends to favour firms with auditable procedures and sector-specific documentation.
Future demand around Southampton appears tied less to new exploration and more to keeping existing energy, marine and industrial assets compliant, available and cost-controlled. The cohort’s lean-service profile tends to favour firms that can stay close to operations, respond to outage windows and handle specialist documentation without the overhead of a large operator. Some consolidation may come through larger energy-service groups absorbing inspection, maintenance and logistics capability, but much of the market is likely to remain relationship-led. Energy transition pressure may also blur boundaries, with hydrocarbon suppliers taking adjacent work in ports, storage and industrial energy infrastructure.
35
Active firms
2026
3
Above £5M
reported turnover
2
Since 2022
incorporations
Key facts
About 8% of the trading cohort reports turnover above £5M (3 of 35 firms) — the rest sits below that revenue band.
5% of the cohort was incorporated since 2022 (2 firms), so a sizeable share is in its first few filing cycles.
Southampton oil and gas activity spans exploration, production, storage and specialist services across the regional energy economy.
The local supplier base sits between upstream activity, fuel logistics and industrial customers, rather than only serving extraction work.
Service-led operating models appear more common than balance-sheet-heavy production businesses in this Southampton cohort.
Top Southampton Oil & Gas companies
Vulcan Offshore Ltd
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsProvides welding, metal fabrication and CNC machining services, including design and onsite support, for offshore, subsea and marine industries. Manufactures and repairs equipment such as cable…
Serves B2B clients in offshore, renewables, subsea, marine, oil and gas, cable-laying and UK manufacturing, including operators needing equipment, repairs or ship mobilisation support.
Financial Health
StableStable · Hiring · 52% CAGR over 4y
Location
Provides oil spill response and preparedness services for the oil and gas industry, including emergency response, incident and crisis management, contingency planning, equipment hire, aerial…
Serves B2B members in the global oil and gas, shipping, port, offshore and shoreline sectors, including operators and organisations responsible for spill preparedness and incident response.
Location
Provides oil spill preparedness and emergency response services for the oil and gas industry, including incident management, equipment hire, dispersant application, aerial surveillance, subsea well…
Serves oil and gas operators, shipping organisations, ports, offshore asset owners, and public or industry bodies responsible for spill preparedness, emergency planning, and response worldwide.
Location
BSA TUBE RUNNER LIMITED
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsManufactures and supplies specialised tube and pipe tooling for installation, removal, testing and maintenance of heat exchangers, boilers and condensers, including tube expanders, cutters, facers,…
Serves B2B engineering and maintenance teams, subcontractors and operators in oil and gas refineries, nuclear and marine sectors, especially organisations working on heat exchangers, boilers,…
Financial Health
HealthyHealthy · Growing · 0% CAGR over 4y
Location
ENVIROS SURVEY & CONSULTANCY LTD
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsProvides geoscience, environmental and survey services for offshore and onshore projects, including geophysical and geotechnical surveys, seismic data acquisition, metocean and environmental studies,…
Serves B2B clients in oil and gas, renewables, infrastructure, subsea cable and deep-sea mining sectors, mainly project developers, operators and engineering teams managing offshore, coastal and…
Financial Health
StableStable · Hiring · 41% CAGR over 4y
Location
WB CIVIL & MECHANICAL LIMITED
Trajectory
5y · 2020–NowFinancial sub-scores
Computed from 5 filingsProvides pipeline engineering and construction services for oil and gas infrastructure, including pipework fabrication, pipeline diversion design, installation and repair, composite pipeline repairs,…
Serves B2B and public-sector buyers in pipeline infrastructure, including oil and gas pipeline operators, energy asset owners, utilities, civil engineering contractors and highway authorities.
Financial Health
WeakWeak · -2% CAGR over 4y
Location
OCEAN INFINITY INNOVATIONS LIMITED
Trajectory
4y · 2022–NowFinancial sub-scores
Computed from 4 filingsDevelops and operates robotic and remotely controlled marine vessels and technology for offshore data collection and maritime operations. Provides subsea survey, inspection and data capture services…
Serves B2B customers in maritime, offshore energy and industrial sectors, including operators needing subsea data, remote operations and marine technology support.
Financial Health
DistressedDistressed · -68% CAGR over 3y
Location
Flo UK Trans Limited
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsSupplies and installs engineered product transfer systems for road transport vehicles, including liquid handling equipment for chemicals, petroleum, LPG and food products, and air‑moving systems for…
Serves B2B road transport operators and fleet owners handling liquids, gases and dry bulk loads, including chemical, LPG, industrial gas, oil and petroleum, food, hygiene, powder, cement, aggregate,…
Financial Health
HealthyHealthy
Location
WILLIAMS MARINE LUBRICANTS LIMITED
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsSupplies and distributes ExxonMobil marine lubricants to commercial and inland vessel operators, including engine, hydraulic, compressor, gear and refrigeration oils and greases, and provides…
Serves B2B marine operators, including fleets of all sizes, inland and coastal vessel operators, fishing vessels and other commercial marine customers across the UK and Europe.
Financial Health
WeakWeak · -66% CAGR over 4y
Location
BPG Solutions
Trajectory
4y · 2021–NowFinancial sub-scores
Computed from 4 filingsProvides oil and gas consulting and technical services including subsurface reservoir evaluation, field development planning, drilling and completions design, production optimisation, facilities…
Serves B2B customers in the oil and gas sector, including operators, asset owners, development teams and investors involved in exploration, field development, production, asset transactions and…
Financial Health
StrongStrong · Hiring · 19% CAGR over 4y
Location
Easygoing Designs Ltd
Trajectory
5y · 2020–NowFinancial sub-scores
Computed from 5 filingsFinancial Health
DistressedDistressed · 0% CAGR over 4y
Location
ENOFLEX LIMITED
Trajectory
3y · 2023–NowFinancial sub-scores
Computed from 3 filingsDevelops and manufactures composite pipeline systems using industrial-scale additive manufacturing. Produces specialised pipes such as SPC and PEEK‑CF for energy infrastructure applications including…
Serves B2B energy infrastructure customers involved in LNG, carbon sequestration and hydrogen projects, including operators and developers needing pipeline solutions for low-carbon energy systems.
Financial Health
StrongStrong · Hiring · 15% CAGR over 2y
Location
CARRICK RESOURCES LIMITED
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsFinancial Health
WeakWeak · -68% CAGR over 4y
Location
QA3 LIMITED
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsProvides on-site and laboratory chemical analysis for the oil, gas and petrochemical sectors, measuring trace contaminants such as mercury, arsenic, oxygen and sulphur, and offering analytical…
Serves B2B clients in the global oil, gas and petrochemical industries, including upstream offshore, midstream and downstream operators, plus organisations managing decommissioning projects.
Financial Health
StrongStrong · Growing, Hiring · 10% CAGR over 4y
Location
Rochem Fyrewash Ltd
Trajectory
5y · 2022–NowFinancial sub-scores
Computed from 5 filingsProvides cleaning systems and chemicals for gas turbine and process compressor maintenance, including compressor washing nozzles, filtration units, wash skids, blade wipes and related equipment used…
Serves B2B operators of gas turbines and process compressors, including power and energy companies, oil and gas firms, combined heat and power plants, petrochemical sites and refineries worldwide.
Financial Health
HealthyHealthy · Hiring · 5% CAGR over 4y
Location
ENGINEERING SOLUTIONS AND SUPPLY LIMITED
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsSupplies and hires flange weld testers and weld isolation tools for hydrostatic testing of piping systems. Acts as a UK distributor for Technom equipment and provides installation support, training…
Serves industrial contractors and facility operators involved in piping system construction and maintenance, primarily in the oil, gas, chemical, petrochemical, nuclear and power sectors.
Financial Health
StableStable · -69% CAGR over 4y
Location
TSL TECHNOLOGY LIMITED
Trajectory
3y · 2023–NowFinancial sub-scores
Computed from 3 filingsDevelops and manufactures electromechanical equipment and components for energy, marine and industrial applications, including downhole logging tools, underwater thrusters, generators, electric…
Serves B2B customers in energy, marine and industrial markets, including oil exploration and production logging/service tool companies, subsea and marine propulsion buyers, and renewable energy…
Financial Health
DistressedDistressed · 0% CAGR over 2y
Location
TECHNODYNE INTERNATIONAL LIMITED
Trajectory
3y · 2023–NowFinancial sub-scores
Computed from 3 filingsProvides engineering design and consultancy for cryogenic and liquefied gas storage tanks, spheres and vessels. Services include mechanical, structural, civil, piping, electrical and process…
Sells to businesses in the energy, petrochemical and industrial gas sectors, serving owners, operators and project teams needing cryogenic and liquefied gas storage tank, sphere and vessel…
Financial Health
HealthyHealthy · Hiring · 19% CAGR over 2y
Location
SRJ TECHNOLOGY LIMITED
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsDevelops and supplies asset integrity management technologies for energy and industrial facilities, including hot bolting flange clamps, leak repair clamps and weldless pipe couplings. Also provides…
Serves B2B asset owners, plant operators and project teams in the energy industry, including offshore, renewables, FPSO and mature asset environments requiring asset integrity and inspection support.
Financial Health
HealthyHealthy · 0% CAGR over 4y
Location
BCD Industrial Ltd
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsProvides industrial fuel polishing services to remove water and particulates from stored fuel. Also installs, repairs and decommissions fuel tanks, undertakes OFTEC tank inspections, pipework…
Serves businesses and site operators across the UK that manage industrial fuel storage, tanks, pipework, separators and drainage assets.
Financial Health
StrongStrong · Growing, Hiring · 6% CAGR over 4y
Location
SDM FUEL SOLUTIONS LIMITED
Trajectory
5y · 2020–NowFinancial sub-scores
Computed from 5 filingsProvides fuel management and engineering services including fuel tank cleaning, fuel testing and sampling, fuel polishing, emergency fuel supply, and delivery of HVO and GTL fuels. Also conducts site…
Serves UK and European businesses and critical facilities that store or rely on fuel, from single-site operators to multi-site organisations needing fuel quality, tank and emergency supply support.
Financial Health
StrongStrong · Growing, Hiring · 51% CAGR over 4y
Location
PCS Holdco Limited
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsSupplies pipeline and construction materials including pipes, pipe fittings, flanges, bolts, gaskets and forged fittings in various material grades. Provides stocked and short‑lead supply for…
Serves B2B customers in the steel, petrochemical, engineering and ship repair industries, including UK and export buyers needing materials for small or large projects and emergency requirements.
Financial Health
StrongStrong
Location
CLEARWELL ENERGY LIMITED
Trajectory
3y · 2023–NowFinancial sub-scores
Computed from 3 filingsSupplies electromagnetic flow assurance technology for the oil and gas industry designed to control mineral scale in wells and pipelines. Systems transmit radio‑frequency signals through tubing to…
Sells to B2B energy customers, primarily oil and gas operators managing onshore and offshore wells and production assets worldwide, including teams responsible for flow assurance, well integrity and…
Financial Health
StrongStrong
Location
EUROTANK ENVIRONMENTAL LIMITED
Trajectory
2y · 2024–NowFinancial sub-scores
Computed from 2 filingsProvides maintenance and environmental services for fuel storage systems, including tank lining, inspection, testing and re‑tightening, fuel quality management, tank and pipeline cleaning, and fuel…
Serves B2B fuel retail and fuelling facility operators, including petrol forecourts, supermarket fuel sites, motorway service areas and downstream retail fuel businesses across the UK.
Financial Health
WeakWeak · -39% CAGR over 1y
Location
SMI
Designs and manufactures pressure‑moulded cable systems, connectors, penetrators and cable harnesses for use in submarines, ships, aircraft and energy infrastructure. Also provides engineering,…
Serves defence and public-sector naval programmes, aerospace OEMs, offshore and renewable energy operators, marine exploration firms and transport infrastructure platform designers operating in…
Location
Pipeline & Construction Supplies Limited
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsSupplies industrial pipeline components including pipes, pipe fittings, flanges, bolts, gaskets and forged fittings. Provides materials in multiple grades from stock or short lead times for…
Serves B2B customers in the steel, petrochemical, engineering and ship repair industries, supplying organisations handling small or large projects across UK and export markets.
Financial Health
HealthyHealthy · Hiring · 5% CAGR over 4y
Location
PCE Solutions Ltd
Trajectory
3y · 2023–NowFinancial sub-scores
Computed from 3 filingsFinancial Health
WeakWeak · 0% CAGR over 2y
Location
I J A S LIMITED
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsSupplies monolithic isolation joints for pipeline cathodic protection, primarily to the gas and oil industry. Also provides flange insulation kits, sacrificial anodes, marker posts and related…
Sells to B2B customers in the UK gas and oil sector, particularly pipeline operators such as British Gas Transco and their subcontractors, as well as buyers responsible for cathodic protection and…
Financial Health
HealthyHealthy · 0% CAGR over 4y
Location
SOUTHWEST TRUCKS LIMITED
Trajectory
3y · 2023–NowFinancial sub-scores
Computed from 3 filingsImports trucks, spare parts and heavy‑duty equipment for the oil and gas downstream sector. Operates haulage services using a fleet of tanker trucks to transport petroleum products for oil industry…
Serves B2B clients in the downstream oil and gas sector, especially petroleum marketers and operators needing tanker haulage, trucks, spare parts and heavy-duty equipment.
Financial Health
WeakWeak · 4% CAGR over 2y
Location
R&M ELECTRICAL INVESTMENTS LIMITED
Trajectory
3y · 2023–NowFinancial sub-scores
Computed from 3 filingsSupplies and distributes electrical products, components and industrial consumables including switchgear, controls, fixings, instrumentation and safety equipment. Provides supply chain and…
Sells to businesses and industrial buyers in the UK and internationally, particularly across oil and gas, petrochemical, marine, defence, data centres, nuclear, industrial, renewables, rail,…
Financial Health
DistressedDistressed · -90% CAGR over 2y
Location
DUVINE LIMITED
Trajectory
3y · 2023–NowFinancial sub-scores
Computed from 3 filingsDesigns and manufactures DC power supply systems, rectifiers, battery chargers and custom power cabinets. Provides impressed current cathodic protection (ICCP) systems with monitoring and control for…
Serves B2B infrastructure and engineering customers in rail, civil engineering, industrial, oil and gas, telecoms and utilities sectors, including project managers and cathodic protection engineers.
Financial Health
StableStable · 0% CAGR over 2y
Location
Green Bow Maritime Limited
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsFinancial Health
DistressedDistressed · 0% CAGR over 4y
Location
ACTIVE FLOW CONTROLS LIMITED
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsDesigns and manufactures gas control and measurement equipment for the gas industry, including pressure reduction stations, metering stations, filters, regulators, valves and skid-mounted modules.…
Serves B2B customers in the UK gas industry, including gas transmission and distribution operators, industrial and commercial contractors, utilities, and SMEs needing gas control and metering…
Financial Health
HealthyHealthy · Hiring · 10% CAGR over 4y
Location
Island OIL Trading
Trajectory
3y · 2023–NowFinancial sub-scores
Computed from 3 filingsTrades and supplies marine fuels (bunkers) to the shipping industry, arranging procurement and delivery of fuel to vessels through a network of trading desks and physical supply operations within an…
Serves B2B customers in local and international shipping markets, including blue-chip shipowners, operators and marine bunker fuel buyers.
Financial Health
StrongStrong · Hiring · 26% CAGR over 2y
Location
MARINE AND RISK CONSULTANTS LIMITED
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsProvides maritime consultancy services including navigation risk assessments, safety management and simulation studies for ports, shipping and offshore energy projects. Also offers hydrographic…
Serves B2B and public-sector maritime clients, including port and harbour authorities, shipping operators, offshore renewable energy developers, oil and gas companies, utilities, and organisations…
Financial Health
StableStable · -2% CAGR over 4y
Location
M.A.B. ENVIRONMENTAL LIMITED
Trajectory
4y · 2023–NowFinancial sub-scores
Computed from 4 filingsFinancial Health
StrongStrong
Location
International Oilfield Supply Co Ltd
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsSupplies equipment and consumables for the oil and gas industry, including industrial hoses, hydraulic fittings, PPE, safety gear, and workwear. Also provides equipment rental, warehousing, hose…
Sells primarily B2B to oil and gas companies, plus industrial and construction businesses. Serves buyers needing oilfield supplies, PPE, hoses, rental equipment and warehousing, with emphasis on…
Financial Health
HealthyHealthy
Location
Jasco Applied Sciences (UK) Limited
Trajectory
3y · 2022–NowFinancial sub-scores
Computed from 3 filingsProvides underwater acoustics consulting and scientific services, including noise impact assessments, acoustic modelling, monitoring and data analysis. Develops ocean acoustic instruments and…
Serves organisations operating in marine and offshore environments, including defence and security bodies, marine construction firms, offshore wind and renewable energy developers, oil and gas…
Financial Health
StableStable · 0% CAGR over 2y
Location
D A BENHAM ENGINEERING LIMITED
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsProvides precision engineering and CNC machining of complex components, sub-assemblies and kits of parts for the aerospace, defence, and oil and gas industries, using advanced machine tools and…
Serves B2B customers in aerospace and defence supply chains, particularly OEMs, plus organisations in the oil and gas sector with requirements for precision-engineered components, assemblies and kits.
Financial Health
StableStable · -65% CAGR over 4y
Location
Perfect Bore Manufacturing Limited
Trajectory
3y · 2022–NowFinancial sub-scores
Computed from 3 filingsProvides precision machining services specialising in deep hole drilling and internal and external surface machining. Offers gundrilling, deep hole boring, honing, CNC turning and grinding, and…
Serves B2B manufacturers and engineering contractors in aerospace, defence, nuclear, oil and gas, automotive and medical sectors requiring precision-machined components or subcontract capacity.
Financial Health
StableStable · 2% CAGR over 2y
Location
ETA-Connect Limited
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsProvides engineering consultancy, project management, and specialist equipment for subsea cable projects. Designs and supplies installation, burial, and handling systems, cable accessories, and…
Serves B2B marine and subsea cable markets, including energy and telecom system owners, suppliers, installers, developers and contractors in power, tidal, offshore wind, oil and gas, and telecoms.
Financial Health
StrongStrong · Growing, Hiring · 11% CAGR over 4y
Location
EUROPUMP MAINTENANCE LIMITED
Trajectory
2y · 2024–NowFinancial sub-scores
Computed from 2 filingsProvides fuel management systems and equipment for commercial fuelling depots, including diesel and AdBlue pumps, storage tanks, tank gauging and leak detection. Offers design, installation,…
Serves UK commercial fleet and fuelling depot operators, including road haulage, rail, bus and coach, marina, blue light, aggregate, food manufacturing and local authority transport customers.
Financial Health
HealthyHealthy · -20% CAGR over 1y
Location
SPC Southampton Limited
Trajectory
5y · 2021–NowFinancial sub-scores
Computed from 5 filingsOperates as a holding company for subsidiaries providing industrial surface preparation and protection services, including abrasive blasting, protective painting and coatings, fireproofing, metal…
Serves infrastructure and industrial organisations, including rail, petrochemical and gas, river and marine, highways, energy and construction operators, plus Ministry of Defence and government…
Financial Health
WeakWeak · 0% CAGR over 4y
Location
ENZYME ENERGY LIMITED
Trajectory
5y · 2020–NowFinancial sub-scores
Computed from 5 filingsFinancial Health
WeakWeak · Hiring · 19% CAGR over 4y
Location
Unlock all 35 leads
Showing 44 of 35 — +0 more with verified decision-maker contacts, live data, and CRM sync.
How Southampton Oil & Gas companies work and how to sell to them
What they do
Southampton oil and gas suppliers usually earn revenue through contracted technical work rather than repeat consumer sales. Income may come from day-rate field teams, fixed-price project scopes, maintenance retainers, equipment hire or resale margin, and framework call-offs tied to port, refinery, marine or offshore assets. Software-style subscriptions are uncommon unless the firm has a monitoring or asset-management platform alongside its services. Pricing tends to follow operational risk: emergency response, confined-window outages and certified inspection work carry different margins from routine logistics or spares supply. The service shape is therefore partly industrial contractor, partly specialist engineering supplier, with proof of safety, insurance and traceability built into the commercial offer.
Who they sell to
Buyers are usually industrial rather than consumer-facing: energy asset operators, port users, marine engineering teams, storage operators, refinery-linked maintenance teams and larger contractors needing local specialist capacity. Decision-makers tend to include operations directors, engineering managers, safety leads, procurement managers and finance signatories where work affects shutdown budgets or insurance exposure. Lower-risk work may be bought through repeat purchase orders or informal supplier relationships; higher-risk scopes often move through RFQs, framework agreements, customer audits and subcontractor pre-qualification. Sales cycles are therefore uneven. A known supplier can win short-notice remedial work quickly, while a new entrant may spend longer proving method statements, certifications and commercial resilience before receiving live work.
What they buy
Most firms in this segment tend to spend on systems and services that make small technical teams easier to schedule, evidence and bill. Relevant categories include field-service management, asset and maintenance tracking, document control, quality and safety software, CRM, quoting tools, accounting, payroll, stock control, fleet management and cyber security. They may also buy specialist recruitment, training, insurance advice, environmental consultancy, legal support for contracts, and marketing aimed at framework inclusion rather than broad consumer demand. Infrastructure spend is often practical: cloud storage for technical documents, mobile devices for field teams, workshop equipment, calibrated instruments, vehicles and facilities that support inspection, repair or logistics work.
Why and how to sell to them
Oil and gas buyers tend to evaluate vendors when operational risk changes: a new framework opportunity, a planned outage, an audit finding, a safety incident, an insurance review, or a customer win that stretches a lean team. Southampton suppliers may also look again at tools and advisers when they diversify into adjacent port, storage or industrial energy work, because documentation and buyer expectations can shift between end markets. Outbound messaging is usually more credible when it links to availability, compliance evidence, utilisation, margin control or faster mobilisation, rather than broad claims about growth. Signals worth watching include recruitment for field roles, new accreditations, tender activity, fleet or premises changes, and directors with recent operational appointments.
How this list is built
Data sources
This list is built from UK Companies House filings, XBRL accounts data, and semantic analysis of each company's public website. Revenue and headcount figures come from the most recent filed accounts; where the company has not filed, values are estimated using a model trained on filed history and peer benchmarks and are labelled as estimates.
Classification
Rather than relying solely on SIC codes, Firmbase classifies each company semantically: the company's website is crawled, an AI model reads what the company actually sells, and the company is placed into the relevant industry and subsectors. SIC codes are used as one signal but not the only one. This means a company that registered under a generic SIC code but pivoted into (for example) fintech is correctly identified as fintech, not as its original SIC category.
Freshness
The underlying company data is refreshed from Companies House continuously; filings appear in the list within days of submission. The curated list ordering is regenerated when the underlying data moves meaningfully (company count changes by more than 5%, a new company enters the top-ranked segment, or the filed-revenue numbers for the top firms change). You can see the last-updated timestamp near the top of the page.
Also in Southampton
Related directories
Frequently asked questions
How many Oil & Gas companies are there in Southampton?
What counts as a Oil & Gas company in this list?
Which are the largest Oil & Gas companies in Southampton?
What do Oil & Gas companies in Southampton actually do?
How does Southampton Oil & Gas compare internationally?
How is this list built and how fresh is the data?
How big are the typical Oil & Gas companies in Southampton?
Are these mostly new or established Oil & Gas companies?
What SIC codes does this use?
What buying signals should I look for?
Push these 35 companies into your pipeline.
Find the right decision-makers, see verified company data, and export your list in seconds.