Company lists · Data refreshed September 2026

Top 18 Oil and gas accounting firms based in Switzerland

RevenueBase identified 31 oil and gas accounting firms headquartered in Switzerland as of September 2026 and tracks 147 professional contacts across them, including 53 with verified work emails and 1 with mobile numbers. Baar is the largest hub.

This list covers oil and gas accounting firms headquartered in Switzerland, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, how directly it supports the match, and when it was last checked. Data refreshed September 5, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row Match evidence on every row Refreshed Sep 5, 2026 86% judged on-target in blind review
31Companies
147Contacts tracked
53Verified emails
1Mobile numbers
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The 18 largest oil and gas accounting firms based in Switzerland

Ranked by team size
Top 18 of 31 oil and gas accounting firms based in Switzerland, ranked by team size, largest first. Data refreshed Sep 5, 2026. Evidence rates how directly each company's own description names oil and gas accounting firms: strong (names it), partial (names part of it), indirect (matched on its full profile rather than the summary shown). Click a count to unlock that company's people.
#CompanyHeadquartersEmployeesContacts
1
Lenz Treuhand AGPartial evidence
Zürich, SwitzerlandHQ checked Sep 5, 202611-5011

“Lenz Treuhand AG is an accounting company based out of Seefeldstrasse 35, Zürich, Canton of Zurich, Switzerland.”

Source: company website · checked Sep 5, 2026
2
Emmenegger Fides AGIndirect evidence
Olten, SwitzerlandHQ checked Sep 5, 20261-108

“Unser Unternehmen bietet hoch stehende Dienstleistungen in den Bereichen Wirtschaftsprüfung, Buchführung und Abschlussberatung sowie Steuer- und Unternehmensberatung an.”

Source: company website · checked Sep 5, 2026
3
Hagmann Treuhand AGPartial evidence
Bern, SwitzerlandHQ checked Sep 5, 202611-507

Accounting/Audit/Tax Advice/Management Consultancy”

Source: company website · checked Sep 5, 2026
4
Fiduservice S.AIndirect evidence
Fribourg, SwitzerlandHQ checked Sep 5, 202611-507

“Comptabilité | Révision | Fiscalité | Administration | Conseils | Salaires | Création d'entreprise”

Source: company website · checked Sep 5, 2026
5
Atca SàrlPartial evidence
Lausanne, SwitzerlandHQ checked Sep 5, 20261-107

“The mission of ATCA is to provide our clients with excellent accounting, tax, financial analysis, business consulting, internal control and audit services.”

Source: company website · checked Sep 5, 2026
6
ChemengineeringIndirect evidence
Baar, SwitzerlandHQ checked Sep 5, 20261-107

“CHEMENGINEERING is active mainly in the O&G industry and the steel industry, serving customers in the following fields of activities: Assistance in commercial activities, as…”

Source: company website · checked Sep 5, 2026
7
HLS & Partner SAIndirect evidence
Vevey, SwitzerlandHQ checked Sep 5, 20261-106

“HLS & Partner is an Audit and Consulting firm which offers a wide range of financial services.”

Source: company website · checked Sep 5, 2026
8
Treuhand-Kanzlei AGIndirect evidence
Chur, SwitzerlandHQ checked Sep 5, 202611-505

“Treuhand, Wirtschaftsprüfung, Buchhaltung & Unternehmensberatung.”

Source: company website · checked Sep 5, 2026
9Sankt Gallen, SwitzerlandHQ checked Sep 5, 20261-105

“Wirtschaftsprüfung Unternehmensberatung Steuerberatung Rechnungswesen”

Source: company website · checked Sep 5, 2026
10
Gb&h Treuhand AGIndirect evidence
Frenkendorf, SwitzerlandHQ checked Sep 5, 20261-104

“Buchhaltung | Steuern | Beratung Dafür stehen wir.”

Source: company website · checked Sep 5, 2026
11
HST Treuhand AGIndirect evidence
Heimberg, SwitzerlandHQ checked Sep 5, 20261-103

“HST Treuhand AG ist Spezialistin in Wirtschaftsprüfung - Wirtschaftsberatung -NPO-Finanzen”

Source: company website · checked Sep 5, 2026
12
Accounting & TAX Point AGIndirect evidence
Freienbach, SwitzerlandHQ checked Sep 5, 20261-103

“Unternehmensberatung Steuern Rechnungswesen Revisionen”

Source: company website · checked Sep 5, 2026
13
Jucker TreuhandIndirect evidence
Pfäffikon, SwitzerlandHQ checked Sep 5, 20261-102

“Buchhaltungen, Steuern, Unternehmensberatungen”

Source: company website · checked Sep 5, 2026
14
Patris Consulting GmbhPartial evidence
Zürich, SwitzerlandHQ checked Sep 5, 20261-102

“We are a Zurich and Zug-based company that is offering high-quality services and we want to be perceived as a very good provider in accounting, auditing and tax matters in the…”

Source: company website · checked Sep 5, 2026
15
Fiduciaire CuennetIndirect evidence
Bulle, SwitzerlandHQ checked Sep 5, 20261-101
Source: company website · checked Sep 5, 2026
16Appenzell, SwitzerlandHQ checked Sep 5, 20261-101

“Buchführung & Abschlusserstellung Lohnabrechnungen / Sozialversicherungen Wirtschaftsprüfung Steuer- & Unternehmensberatung”

Source: company website · checked Sep 5, 2026
17
Ribo TreuhandIndirect evidence
Gstaad, SwitzerlandHQ checked Sep 5, 20261-101

“Buchhaltung, Treuhand, Wirtschaftsberatung, Wirtschaftsprüfung, Revision, Steuerberatung”

Source: company website · checked Sep 5, 2026
18
Oltreu GmbhIndirect evidence
Olten, SwitzerlandHQ checked Sep 5, 20261-101

“Wirtschaftsprüfung, Unternehmensberatung und Treuhand (Buchführung, Abschlussberatung und Steuern)!”

Source: company website · checked Sep 5, 2026

Showing 18 of 31 oil and gas accounting firms based in Switzerland

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Oil and gas accounting firms based in Switzerland at a glance

As of Sep 5, 2026
1-10Median size (employees)
BaarLargest hub · 2 HQs
1Contacts with mobile numbers
Sep 5, 2026Data refreshed

Companies by employee count

1-10
25
11-50
5

Verified emails by last verification

0–30
48
31–60
5
61–90
0
90–180
0
180+
0

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among oil and gas accounting firms, so some rows will be adjacent to the category rather than pure plays. The description and evidence rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in Switzerland whose own description of what they do matches “oil and gas accounting firms”. Matching reads each company's description, not its industry code or its name.
What we exclude
Companies whose own description does not clearly place them among oil and gas accounting firms, and records with no verified work email. Companies headquartered outside Switzerland are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and an evidence rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 53 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 5, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

How many oil and gas accounting firms are there based in Switzerland?

RevenueBase identified 31 oil and gas accounting firms headquartered in Switzerland as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Lenz Treuhand AG, headquartered in Zurich, tops this list with the largest team on record.

Which city has the most oil and gas accounting firms?

Baar leads with 2 headquartered companies, followed by Chur (2) and Geneva (2).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 53 verified decision-maker contacts tracked across these 31 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 5, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase SmartSearch, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.