Updated 01-02-2023 05:01 PM
I earned this in a Sandbox game, I had to have 200,000 in the account at the same time. Set up a game with unlimited money so you can build as many expensive building as it takes to bring money into your swiss account.
The fastest way to earn this is to have several banks sending money to your swiss account. You also will need to have the building permit edict active too.
Once you have that just build everything possible and eventually you will have 200,000 in your swiss account. It took me a couple hours to get the full 200,000 into the account.