You need to declare the capital increase Federal Tax Administration (FTA). You need to hand in the notary deed stating the capital increase and form 3. You need to file these documents at the latest 30 days after the quarter in which the capital increased happened. You can find form 3 here: https://www.estv.admin.ch/dam/estv/de/dokumente/sta/formulare/3.qdf.download.qdf/3-d.qdf