To add to the above comments, the 2019 Ct. Zurich tax instructions on p.29 say (translation):

"It is only possible to refrain from filing a special tax return for the gift tax:
- for gifts to the spouse or to the registered same-sex partner;
- for gifts to a descendant;
- for occasional gifts not exceeding the value of CHF 5,000 each.
No inheritance or gift tax is payable on such gifts."

https://www.zh.ch/content/dam/zhweb/...9_HA%20DEF.pdf