Company lists · Data refreshed September 2026

Top 25 Audit and assurance firms based in Switzerland

RevenueBase identified 108 audit and assurance firms headquartered in Switzerland as of September 2026 and tracks 1,587 professional contacts across them, including 950 with verified work emails. Zurich is the largest hub.

This list covers audit and assurance 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, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 19, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, 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 RevenueBase Smart Search rating on every row Refreshed Sep 19, 2026 86% judged on-target in blind review
108Companies
1,587Contacts tracked
950Verified emails
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The 25 largest audit and assurance firms based in Switzerland

Ranked by team size
Top 25 of 108 audit and assurance firms based in Switzerland, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to audit and assurance firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidenceZürich, SwitzerlandHQ checked Sep 19, 20261,001-5,0001,090 contacts →

Partial evidence

“BDO is one of the leading audit, accounting and consulting firms in Switzerland.”

Source: RevenueBase Database · checked Sep 19, 2026
2Indirect evidenceZürich, SwitzerlandHQ checked Sep 19, 202651-20034 contacts →

Indirect evidence

“Swiss legal service provider.”

Source: RevenueBase Database · checked Sep 19, 2026
3Indirect evidenceStadtkreis 8 Riesbach, SwitzerlandHQ checked Sep 19, 202611-5020 contacts →

Indirect evidence

“We have been acknowledged as an independent, flexible and trustworthy consulting firm since 1946.”

Source: RevenueBase Database · checked Sep 19, 2026
4Indirect evidenceLausanne, SwitzerlandHQ checked Sep 19, 202611-5020 contacts →

Indirect evidence

“Depuis plus de 30 années, Fidexaudit accompagne ses clients dans tous les domaines de la fiduciaire.”

Source: RevenueBase Database · checked Sep 19, 2026
5Indirect evidenceSiebnen, SwitzerlandHQ checked Sep 19, 202651-20017 contacts →

Indirect evidence

“KMU Treuhand & Revision – für Sie da.”

Source: RevenueBase Database · checked Sep 19, 2026
6Indirect evidenceLangenthal, SwitzerlandHQ checked Sep 19, 202611-5017 contacts →

Indirect evidence

“Gfeller + Partner AG ist ein mittelständisches Dienstleistungsunternehmen, welches Wirtschaftsprüfungs, Steuer- und Beratungsdienstleistungen anbietet.”

Source: RevenueBase Database · checked Sep 19, 2026
7Indirect evidenceBasel, SwitzerlandHQ checked Sep 19, 202611-5014 contacts →

Indirect evidence

“Wir entwickeln für Sie individuelle und auf Ihre Bedürfnisse angepasste Lösungen in den Bereichen Treuhand, Wirtschaftsprüfung, Steuern und Unternehmensberatung- Treuhand: Wir…”

Source: RevenueBase Database · checked Sep 19, 2026
8Indirect evidenceLiestal, SwitzerlandHQ checked Sep 19, 202611-5014 contacts →

Indirect evidence

“Die Duttweiler Treuhand AG ist Ihre Spezialistin für Buchführungen und Rechnungswesen, Ihre Expertin für Steuerberatungen, Wirtschaftsprüfungen, Unternehmensberatungen und…”

Source: RevenueBase Database · checked Sep 19, 2026
9Indirect evidenceChur, SwitzerlandHQ checked Sep 19, 202611-5013 contacts →

Indirect evidence

“Treuhand (Rechnungswesen, Abschlusserstellung, Steuern)- Wirtschaftsprüfung (Abschlussprüfung, spezialgesetzliche Prüfung, Unternehmensberatung)- Immobilien…”

Source: RevenueBase Database · checked Sep 19, 2026
10Indirect evidenceZürich, SwitzerlandHQ checked Sep 19, 202611-5011 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 19, 2026
11Partial evidenceStadtkreis 3 Wiedikon, SwitzerlandHQ checked Sep 19, 202611-5010 contacts →

Partial evidence

“Ostschweizerische Treuhand Zürich AG, short OTG, has been in business since 1918 as an accredited audit firm conducting full and limited audits.”

Source: RevenueBase Database · checked Sep 19, 2026
12Indirect evidenceZofingen, SwitzerlandHQ checked Sep 19, 202611-509 contacts →

Indirect evidence

“We are independent auditors, tax advisors and accountants.”

Source: RevenueBase Database · checked Sep 19, 2026
13Indirect evidenceBasel, SwitzerlandHQ checked Sep 19, 202611-509 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 19, 2026
14Partial evidenceZürich, SwitzerlandHQ checked Sep 19, 202611-509 contacts →

Partial evidence

“CONTROVA AG was founded in 2004 in Zug as BCS Audit AG and renamed CONTROVA AG in 2012.”

Source: RevenueBase Database · checked Sep 19, 2026
15Indirect evidenceMorrens, SwitzerlandHQ checked Sep 19, 202611-509 contacts →

Indirect evidence

“Une fiduciaire à visage humain La Fiduciaire Staehli, c’est avant tout une écoute et une gamme de services personnalisés pour répondre efficacement à vos soucis administratifs.”

Source: RevenueBase Database · checked Sep 19, 2026
16Indirect evidenceLugano, SwitzerlandHQ checked Sep 19, 20261-108 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 19, 2026
17Indirect evidenceOlten, SwitzerlandHQ checked Sep 19, 20261-108 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 19, 2026
18Indirect evidenceLuzern, SwitzerlandHQ checked Sep 19, 20261-107 contacts →

Indirect evidence

“Die Lufida-Revision stellt Unternehmen aus allen Branchen ihre Dienstleistungen als unabhängiges und flexibles Wirtschaftsprüfungs- und Beratungsunternehmen zur Verfügung.”

Source: RevenueBase Database · checked Sep 19, 2026
19Partial evidenceBern, SwitzerlandHQ checked Sep 19, 202611-507 contacts →

Partial evidence

“Accounting/Audit/Tax Advice/Management Consultancy”

Source: RevenueBase Database · checked Sep 19, 2026
20Indirect evidence4010, SwitzerlandHQ checked Sep 19, 202611-507 contacts →

Indirect evidence

“Unsere seit über 40 Jahren bestehende Gesellschaft ist spezialisiert auf die Betreuung und Beratung von mittelständischen Unternehmen (KMU), von Personalvorsorgeeinrichtungen…”

Source: RevenueBase Database · checked Sep 19, 2026
21Indirect evidenceZug, SwitzerlandHQ checked Sep 19, 20261-107 contacts →

Indirect evidence

“Tax Consultancy We consult and guide companies sector-independent in national and international corporate tax law (corporate profit tax, tax on capital, withholding tax, stamp…”

Source: RevenueBase Database · checked Sep 19, 2026
22Partial evidenceLausanne, SwitzerlandHQ checked Sep 19, 20261-107 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 19, 2026
23Partial evidenceVevey, SwitzerlandHQ checked Sep 19, 20261-106 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 19, 2026
24Indirect evidenceGenève, SwitzerlandHQ checked Sep 19, 202611-506 contacts →

Indirect evidence

“The Cf Compagnie fiduciaire group has existed in Geneva since 1991, when current founding Partner Christian Furrer founded our first entity, Cf Compagnie fiduciaire de gestion sa.”

Source: RevenueBase Database · checked Sep 19, 2026
25Indirect evidenceChur, SwitzerlandHQ checked Sep 19, 202611-505 contacts →

Indirect evidence

“Treuhand, Wirtschaftsprüfung, Buchhaltung & Unternehmensberatung.”

Source: RevenueBase Database · checked Sep 19, 2026

Showing 25 of 108 audit and assurance firms based in Switzerland

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Audit and assurance firms based in Switzerland at a glance

As of Sep 19, 2026
59.9%Verified-email coverage
14.7Average contacts per company
1-10Median size (employees)
13.0%Largest-city concentration · Zurich
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
75
11-50
28
51-200
2
1,001-5,000
1

Email recency for this list is measured worldwide rather than for Switzerland, so it is reported there. Company counts and contact totals on this page are exact for Switzerland, over 108 companies.

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 audit and assurance firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search 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 Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in Switzerland whose own description of what they do matches “audit and assurance firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names audit and assurance firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among audit and assurance 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 its RevenueBase Smart Search 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, 950 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 19, 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

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names audit and assurance firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many audit and assurance firms are there based in Switzerland?

RevenueBase identified 108 audit and assurance 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?

BDO Switzerland, headquartered in Zurich, tops this list with the largest team on record.

Which city has the most audit and assurance firms?

Zurich leads with 14 headquartered companies, followed by Zug (7) and Geneve (5).

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 950 verified decision-maker contacts tracked across these 108 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 19, 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 Smart Search, 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.