What works for a Swiss client

A Swiss client is one created with the country Switzerland. It books in CHF (EUR is also allowed, any other currency is refused) on the KMU chart of accounts; the German chart SKR03 cannot be chosen for it. Its tax ID is the UID (VAT no.), written CHE-123.456.789; the app checks the check digit and a Swiss postal code has four digits. There is nothing to switch on, this follows from the country.
Parts of the settings are hidden for a Swiss client: the DATEV and Payroll tabs do not appear (payroll exists only for entities in Germany), and the Company profile has no tax number, no small-business option and none of the German tax office options.
These are not available yet and are refused: recording a payment on a booking, assigning or confirming bank lines, the cash book, down payment, partial and closing invoices, the DATEV export, the VAT return with its ZM list and working paper, the trial balance, BWA, P&L (GuV) and the account drill-down, and a file of opening balances. They still use German SKR03 system accounts.
When you try one of them the app answers: This client keeps the KMU chart of accounts. Bank and payment postings, the cash book, down payment invoices, the DATEV export, the VAT return, SuSa and BWA still use SKR03 system accounts and are not available for it yet. This is not a fault and no setting changes it. Nothing is booked when it appears.
The chart check blocks nothing else. Documents, contacts, invoices and quotes, dunning and the bookings export as CSV or ZIP stay open, so you can hand the bookings to your Swiss advisor in a file.
Much of the content follows German rules: the checks before an invoice is finalized cite section 14 UStG, dunning interest and fee follow German law (section 288 BGB), and the retention periods are the German ones (section 147 AO). The app gives no Swiss legal advice; ask your Swiss tax advisor what applies to you.
Entering the data can fail with these messages: The UID is not valid. Expected CHE-123.456.789 with a valid check digit., This currency does not fit the client's country. A German client books in EUR, a Swiss one in CHF or EUR., and This chart of accounts does not fit the client's country.