The loss or theft of a Swiss ID document abroad must be reported as soon as possible to the local police as well as to the relevant Swiss representation.
A police report (declaration of loss) is also required to make it possible to prepare a new identity document, such as a temporary passport. Some countries may require such a document in order to leave their territory. It can also be useful when seeking reimbursement from an insurance company.
Swiss passports/identity cards which have been reported lost or stolen to a Swiss representation are entered in a Federal Office of Police (fedpol) file, and if subsequently recovered must not be used in an ID check or for travel, to avoid future difficulties. They are to be quickly returned to a Swiss authority for destruction.