Switzerland formats its IBAN in 21 characters with the BBAN pattern ^[0-9]{5}[A-Z0-9]{12}$: a numeric clearing number followed by an alphanumeric account field.
Breakdown
The official registry example is CH93 0076 2011 6238 5295 7, a SWIFT registry test value rather than a real account:
CH93- country code and IBAN check digits00762- the 5-digit bank clearing number, known as the IID (institution identification)011623852957- the 12-character account number, zero-padded, letters permitted
The clearing number system
The IID is assigned by SIX Interbank Clearing and identifies the bank (and sometimes a head-office region) within the Swiss SIC payment system. Cantonal banks, the large universal banks and PostFinance each occupy familiar ranges. There is no separate branch field and no domestic check digit in the Swiss BBAN; integrity relies on the IBAN’s MOD-97 check digits alone.
A distinctly Swiss feature is the QR-bill. Since the retirement of the old orange and red payment slips, Swiss invoices carry a QR code containing either a normal IBAN or a QR-IBAN. QR-IBANs are built on a reserved clearing range (30000-31999) and must travel with a 27-digit QR reference; regular banking apps will reject a QR-IBAN entered as a plain beneficiary IBAN. A format validator cannot tell you the payment context, so knowing this distinction matters when Swiss payments fail despite a “valid” IBAN.
Currency and SEPA context
Switzerland is not an EU member and keeps the Swiss franc, but it joined the SEPA schemes, so euro transfers to and from CH IBANs use standard SEPA rails. Domestic CHF traffic uses the same IBANs over the SIC system. Liechtenstein’s LI IBANs share the identical BBAN structure, reflecting the two countries’ integrated financial infrastructure.
Validity remains structural only. A 21-character string that passes the checksum may reference a closed account or an unassigned clearing number, and it says nothing about the holder’s identity. Name-matching services in the style of the EU’s Verification of Payee are the safeguard against paying a well-formed number that belongs to the wrong person.