Anyone opening a bank account in Switzerland for an operating company signs a Form K almost every time. It is one of the model forms of the Swiss banks’ due diligence agreement (CDB 20) and answers a different question from the better-known Form A: not who the assets belong to, but who controls the company.
Who it applies to
Form K covers unlisted legal entities and partnerships that are operational, meaning they run a trading, manufacturing or service business. Companies without operations, the domiciliary companies, still use Form A. Holding companies that own operating subsidiaries are not treated as domiciliary companies under CDB practice and therefore also receive a Form K.
The three-step cascade
First, the controlling person is whoever holds, directly or indirectly, alone or acting in concert, at least 25 percent of the votes or capital. Second, if nobody qualifies, it is whoever controls the company in another recognisable way, for example through veto rights, financing or a shareholders’ agreement. Third, if that also yields no one, the managing person is named as a fallback. The form must show at which step the person was identified.
What the supervisory board objects to
The published leading cases of the CDB supervisory board show recurring errors. A Form K that names a person without stating on what basis they are the controlling person is insufficient. If a domiciliary company holds 25 percent or more of the contracting party, its beneficial owners must be listed directly on the Form K, not the domiciliary company itself. And an entry in the bank’s system does not replace the signed form.
Form K and the transparency register
The logic resembles the identification of beneficial owners under the TJPG, in force since 1 October 2026. Because financial intermediaries will be able to report discrepancies with the transparency register, the Form K and the register filing should match, or their difference should be explainable. Anyone administering a family holding should review both together.
In practice
The form is a declaration by the contracting party that the financial intermediary must check for plausibility. Changes in shareholdings, an inheritance split or a new shareholders’ agreement call for a new form. Signed versions belong to the mandate with version history, so an audit can see which declaration applied when. The underlying concept is explained under controlling person. Thresholds in other countries are listed in our UBO threshold overview.