Kernrechtsfrage
Whether the cantonal authority had to respect an alleged fiscal domicile agreement under the principle of good faith.
Extrahierter Entscheid
No. Any such agreement would be ineffective because the tax authority lacked competence to bind another cantonal service and the alleged domicile arrangement could not override the legal rules.
Extrahierte Begründung
The court held that good faith protects only conditions met by competent authorities acting within their powers. A tax-based arrangement on domicile could not legally create entitlement to health-insurance subsidies or bind the health-insurance service.