Liechtenstein 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, identical to the Swiss layout.
Breakdown
The official registry example is LI21 0881 0000 2324 013A A, a SWIFT registry test value rather than a real account:
LI21- country code and IBAN check digits08810- the 5-digit bank clearing number, known as the IID (institution identification)0002324013AA- the 12-character account number, zero-padded, letters permitted
The clearing number system
Liechtenstein’s banks clear through SIX Interbank Clearing, the same infrastructure that serves Switzerland, and their IIDs are drawn from the same registry. There is no separate branch field and no domestic check digit in the BBAN; integrity relies on the IBAN’s MOD-97 check digits alone. The country’s banking sector is small but internationally oriented - the Liechtensteinische Landesbank, LGT Bank and a handful of private banks account for most of the IIDs in circulation.
Currency and SEPA context
Liechtenstein is not an EU member and uses the Swiss franc under a currency union with Switzerland, but it joined the SEPA schemes, so euro transfers to and from LI IBANs use standard SEPA rails. Domestic CHF traffic uses the same IBANs over the SIC system, reflecting how tightly the two countries’ financial infrastructure is integrated.
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.