OMTax: The digital answer to the OECD minimum tax
The introduction of the minimum tax posed major challenges for the Swiss tax authorities. As no system existed previously that could map these complex rules, a completely new IT solution had to be developed
Since January 1, 2025, a far-reaching change has been in force in Switzerland: the OECD/G20 minimum tax of 15 percent for large, internationally active corporate groups. Behind the scenes is the ambitious IT project OMTax, which makes the implementation possible in the first place. The efficient system was developed by emineo and the Swiss Tax Conference SSK.
OECD/G20 minimum taxation
Switzerland introduced the OECD/G20 minimum tax rate on January 1, 2024, which will be implemented in the form of a national supplementary tax. This provides for large, internationally active corporate groups with an annual turnover of more than 750 million euros to pay at least 15% tax on their profits. The aim of the supplementary tax is to prevent the outflow of tax revenue abroad and to create stable framework conditions. Around 140 countries, including Switzerland, have committed to introducing minimum taxation. In the referendum in June 2023, the people and cantons approved this reform by a clear majority.
A new tax requires a new IT system
The introduction of the minimum tax posed major challenges for the Swiss tax authorities. As there was previously no system that could map these complex rules, a completely new IT solution had to be developed. The requirements for this were high: the system had to cover the requirements of all cantons, be easy for companies to use and comply with strict data protection guidelines. In addition, the implementation schedule was more than ambitious: the new IT solution had to be ready for productive use by January 1, 2025 for the first tax period of the Swiss Qualified Domestic Minimum Top-up Tax (QDMTT).
In view of the tight schedule and the high complexity of the issue, the cantonal and federal tax administrations decided that the Swiss Tax Conference SSK should develop a standardized solution for all 26 cantons. The advantages of a common IT system are obvious: it not only reduces costs, but also ensures that everyone involved works with the same standards so that the new tax rules can be implemented smoothly and efficiently.
The contract to develop the system was awarded to the Swiss software engineering company emineo. emineo impressed with its extensive experience in implementing complex IT projects in a very short space of time. In addition, the collaboration with SSK had already proven itself in the successful development of the web application BVTax (Business Valuation Tax), the joint application of the cantonal tax administrations for the valuation of unlisted securities.
Bundled and wide-ranging experience
Based on the legal basis of minimum taxation, the project partners designed and developed the central web application OMTax – OECD Minimum Taxation. The close collaboration between tax experts and IT specialists, all of whom had already successfully worked on various digitalization projects, proved to be a decisive success factor. Even before the official start of the project in April 2023, the federal government and the SSK set up an ad hoc working group that brought together experts from the cantonal tax administrations and the Federal Tax Administration with extensive knowledge of corporate tax law.
"The development of OMTax posed a particular challenge due to the novel subject matter, the regulations that had not yet been finalized and the tight timeframe. However, thanks to an agile approach and an extremely competent team of experts and developers, this test was successfully overcome."
Use of existing components and proven technology as a basis
Another success factor was the reuse of proven elements: Existing software components from BVTax or the infrastructure of the Federal Office of Information Technology and Telecommunications could be used for OMTax, which shortened the development time and minimized risks. The new IT system also ensures that data sovereignty remains with the Swiss authorities and that the strict requirements of the OECD and the Data Protection Commissioner with regard to data protection are complied with. Before the official go-live, OMTax was tested in several test cycles not only by security specialists and tax authorities, but also by companies. The IT system was comprehensively tested by potentially taxable business units from 20 large companies from different sectors and with various case constellations. Their feedback was incorporated directly into the further development of the system. OMTax was designed to be intuitive to use. The application is integrated into the federal government’s ePortal, which companies are already familiar with.
A punctual starting signal
Despite the tight schedule, OMTax went live as planned on January 1, 2025. The first few months of operation will be closely monitored by emineo and the SSK in order to implement any adjustments quickly. With OMTax, Switzerland is optimally prepared not only technically but also organizationally for the challenges of international minimum taxation. The system is also flexible enough to support the international supplementary tax, the Income Inclusion Rule IIR, which came into force on January 1, 2025, as well as any future requirements such as the activation of the Undertaxed Payment Rule UTPR.
The first revenues from the new tax are expected in 2026 and are estimated at up to CHF 2.5 billion. OMTax is an example of successful collaboration between specialist and IT experts. With innovative approaches and a clear focus on the benefits for all parties involved, the project shows how complex tax requirements can be implemented efficiently.
About the Swiss Tax Conference
The Swiss Tax Conference (SSK), founded in 1919, is an association pursuant to Art. 60 et seq. ZGB (SWISS CIVIL CODE). Its members are the cantonal tax administrations and the Federal Tax Administration (FTA). The SSK promotes the standardization of tax practice and the exchange of experience. Working groups and commissions deal with issues and draw up non-binding recommendations for the cantons. It works in a militia system, i.e. its members work full-time in the cantonal tax administrations or the FTA.
Contact
Stefan Rüttimann
Business Unit Lead Software Engineering
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