Sometimes people forget that they have vested benefits; this is especially true when foreign workers leave Switzerland definitively. The brochure entitled “Vested benefits: don’t forget your retirement assets!” explains what vested benefits are and sets out the various situations where action needs to be taken. It also provides information on where help can be obtained if someone suspects that they have due to them vested benefits they had forgotten about.

https://www.bsv.admin.ch/bsv/en/home/social-insurance/bv/grundlagen-und-gesetze/grundlagen/vergessene-freizuegigkeitsguthaben.html