Fiduciary Offices

William Diana Consulting 

Seon · Since 2006

ACV WILLI Treuhand + Immobilien AG Mels 

Mels · Since 2015

The core activity of Willi Treuhand & Immobilien GmbH encompasses three main areas: 1. **Real Estate**: The company offers real estate services, including renting and buying properties, marketing and managing properties. 2. **Trust Services**: The company provides trust services, including support with asset management and transaction processing. 3. **Business Consulting**: The company offers business consulting services, including strategic consulting and support in solving business problems. The company positions itself as a competent partner for private individuals and companies in the regions of Sarganserland, Walensee, Rheintal, and Graubünden.

Wimag Management AG 

Zurich · Since 2009

The core activity of WIMAG Management AG is the provision of services to the gastronomy industry, particularly in the areas of: * Accounting and finance (online accounting, financial analysis, cost optimization) * Human resources management (HR department, L-GAV issues, termination letters, medical certificates) * Consulting and coaching (mentoring, strategic issues, restructuring, company formations, business purchases/sales) * Partner management (networking, purchasing optimization, special conditions) The company positions itself as a partner and trustee for gastronomy businesses, offering comprehensive services to enable customers to focus on their core business.

WinFinanz GmbH 

Oberägeri · Since 2018

The core activity of WinFinanz GmbH is the provision of services in the field of finance and accounting, in particular: accounting and financial statement consulting, reporting and audit support, personnel administration and social insurance, tax consulting, and temporary bookkeeping and payroll services. The company thus provides comprehensive support in the areas of finance, personnel and controlling, to support companies in fulfilling their legal requirements and optimizing their financial management.

Winhil GmbH 

Hinwil · Since 2015

Winhil GmbH provides accounting and SME support services, including company formation, financial accounting, payroll accounting, accounting closing, tax and VAT services, and advisory.

Winhofer GmbH 

Urdorf · Since 2011

The core activity of Winhofer GmbH is the provision of services in the field of trust, particularly in accounting, financial reporting, payroll and personnel administration, tax returns, collection and company formation. Specifically, this includes: * Accounting: Setting up and maintaining financial, accounts receivable and accounts payable accounting * Financial reporting: Preparing monthly or quarterly interim financial statements, annual financial statements and VAT returns * Payroll and personnel administration: Maintaining payroll accounting, preparing payroll statements and payroll certificates, withholding tax returns, registration and deregistration of social insurance * Tax returns: Preparing tax returns and consulting in the field of social insurance * Collection: Accounts receivable management and dunning * Company formation: Supporting the formation of companies The company offers these services as an outsourcing solution for companies to relieve them of administrative tasks and enable them to focus on their core business.

WINSTON BAYA SA 

Geneva · Since 2019

Winston Baya (formerly ACCs SA) provides fiduciary services, particularly in the areas of: company formation, restructuring and sale; tax planning and consulting for companies and individuals; accounting and financial management; labor law and personnel administration; asset management and planning; international tax planning and consulting; and the establishment and administration of trusts and holdings. The company's core activity is the provision of fiduciary services, specifically supporting companies and individuals in the formation, management and planning of their financial and tax affairs.

WinTax Treuhand GmbH 

Winterthur · Since 2017

The core activity of WinTax Treuhand GmbH is the provision of trust and consulting services in the field of finance, particularly support with tax returns.

Winti Treuhand GmbH 

Winterthur · Since 2022

Winti Treuhand GmbH provides fiduciary and accounting services, including ongoing bookkeeping, preparation of financial statements, VAT returns and payroll processing. The firm also assists private clients with tax returns, tax representation, budget advice and support in debt-related situations.

WIPA Treuhand AG 

St. Gallen · Since 2010

WIPA Treuhand AG provides fiduciary and advisory services in tax law, commercial and corporate law, and accounting administration. Services include representation in tax proceedings and tax-criminal matters, tax rulings and assessments, bookkeeping and financial-statement advice, as well as commercial-register and succession-related services.

Wipolero Treuhand AG 

Hünenberg · Since 2003

Wipolero Treuhand AG provides fiduciary and corporate advisory services, including international corporate structuring, tax planning and compliance, accounting, payroll administration and trustee functions. The firm cooperates with external legal and audit partners for matters requiring specialised expertise.

Wipolero Treuhand Schweiz AG 

Hünenberg · Since 2005

Wipolero Treuhand Schweiz AG is a fiduciary and advisory firm focused on international corporate consulting, tax and accounting services. Its offerings include advice on international corporate structures, establishment and support of headquarters, company formation and restructuring, bookkeeping and financial statement consulting, tax planning and VAT matters, payroll administration and controlling, with cooperation from external legal and audit partners.

WIP Wirtschaftsprüfungs GmbH 

Zurich · Since 1997

The core activity of WIP Wirtschaftsprüfung is the provision of auditing services, in particular the performance of regular and limited audits, as well as special and commissioned audits for companies.

Wiro Treuhand- und Revisionsgesellschaft AG 

Lucerne · Since 1978

The core activity of WIRO Treuhand- und Revisionsgesellschaft AG is the provision of consulting services in the trust area, particularly in the following fields: * Auditing and examination of companies, including limited and ordinary audits as well as examination of capital measures * Accounting and bookkeeping, including payroll accounting and internal management accounting * Trust services, including administration and management of properties and foundations * Consulting in the areas of inheritance law, wills and estate administration * Support in the founding, financial optimization and auditing processes of companies, particularly SMEs. The company thus offers comprehensive services in the field of financial and accounting consulting.

Wirtschafts-Testat AG 

Basel · Since 1981

Wirtschafts-Testat AG is a fiduciary services firm offering statutory auditing, accounting, tax and pension advisory, and business consultancy. Services include audits for corporations and foundations, financial and payroll accounting, tax planning, controlling and company valuation.

WisCo GmbH 

St. Gallen · Since 2024

WisCo GmbH provides CFO-as-a-Service offerings, including fractional and interim CFO services, start-up advisory and board mandates. Its services cover finance and controlling advisory, project management, ERP and FP&A implementations, post‑merger integration and the establishment of internal control and transfer pricing frameworks.

WISTAG Revision AG 

Thun · Since 1981

WISTAG Revision AG carries out audit mandates and provides audit services for companies, including statutory (share-capital) audits, ordinary and limited audits, internal audits, capital increase/decrease and merger audits, and special examinations. Audit mandates are handled by WISTAG Revision AG as a 100% subsidiary of WISTAG Treuhand AG; both firms are recognized by the Swiss Federal Audit Oversight Authority.

WISTAG Treuhand AG 

Thun · Since 1974

WISTAG Treuhand AG provides auditing, tax advisory, accounting and payroll services, as well as business consulting. Audit mandates are processed via the subsidiary WISTAG Revision AG, and both entities are recognized by the Swiss Federal Audit Oversight Authority.

Witrag Management Consultants AG 

Zug · Since 1989

Witrag Management Consultants AG is a management consulting firm that provides advisory and support services to companies across various industries. The firm emphasizes a personal and discreet approach in its client engagements.

Wiveus Treuhand GmbH 

St. Gallen · Since 2022

Wiveus Treuhand GmbH provides fiduciary and accounting services to private clients and small and medium-sized enterprises. Services include bookkeeping and annual financial statements, tax services, payroll administration, insurance and legal advice (in cooperation with partners), company formation and succession planning, and estate and pension advice.