What is a BLZ Code?

A BLZ code (German: Bankleitzahl, meaning "bank routing number") is an 8-digit numerical code used to identify banks and their branches within the German domestic payment system. It was introduced by Deutsche Bundesbank to standardise and automate the routing of payments through Germany's clearing network.

Every bank and savings institution authorised to participate in German payment systems is assigned one or more BLZ codes. The code identifies not just the institution but also the geographic processing location responsible for clearing the payment.

BLZ Code Structure

The 8 digits of a BLZ code are divided into three sections:

• Digit 1 (Clearing Circle / Bankenplatz): Identifies the banking region. Values 1–8 map to specific German clearing cities: 1 = Berlin, 2 = Hamburg, 3 = Hannover, 4 = Düsseldorf, 5 = Frankfurt am Main, 6 = Karlsruhe / Stuttgart, 7 = Munich, 8 = Leipzig.
• Digits 2–3 (Sub-region / Banking Group): Further identify the banking group or sub-region within the clearing circle.
• Digits 4–8 (Institution / Branch Identifier): Uniquely identify the specific bank or branch within that sub-region.

Example: BLZ 20010020 belongs to Postbank in Hamburg (clearing circle 2).

What is a BLZ Code Used For?

• Domestic bank transfers: Historically used alongside a Kontonummer (account number) to route payments within Germany before SEPA.
• Cheque processing: Printed on German cheques for automatic sorting and clearing.
• IBAN composition: Embedded within the German IBAN at positions 5–12, so that existing routing logic continues to work under the SEPA framework.
• Internal bank operations: Banks continue to use BLZ codes internally for transaction routing and reconciliation.
• ATM and POS identification: Used within the German banking infrastructure to identify the issuing institution.

BLZ Codes and SEPA / IBAN

Since 1 February 2014, SEPA (Single Euro Payments Area) replaced BLZ + Kontonummer with IBAN for all euro-denominated credit transfers and direct debits in Germany. However, BLZ codes remain relevant for two key reasons:

• The BLZ is embedded directly in the German IBAN: DE + 2 check digits + 8-digit BLZ + 10-digit account number. Knowing the BLZ allows you to verify which bank issued a given IBAN.
• Some legacy systems, internal bank processes, and older integrations still reference BLZ codes directly.

For any new payment or transfer within the EU, always use the full IBAN rather than the BLZ + account number combination.

BLZ Code vs. IBAN vs. SWIFT Code

• BLZ code (8 digits): Identifies a specific German bank or branch. Used in Germany's domestic context and embedded in German IBANs.
• IBAN (22 characters for Germany): Fully identifies the account for SEPA and international transfers — format: DE + 2 check digits + 8-digit BLZ + 10-digit account number.
• SWIFT / BIC code: Identifies the bank globally. Required alongside the IBAN for non-SEPA international wire transfers.

Where to Find Your BLZ Code

• Bank card: May be printed on some German bank cards under account details.
• Bank statements: Listed alongside your account number (Kontonummer).
• Online banking portal: Found in the account details or settings section.
• Your IBAN: Digits 5–12 of your German IBAN are your BLZ code.
• Deutsche Bundesbank directory: The official published list of all active BLZ codes, updated regularly by the Bundesbank.

Common Mistakes and Things to Be Careful Of

• Using BLZ for SEPA payments: Since 2014, SEPA payments require an IBAN — not a BLZ + Kontonummer. Attempting to use the old format in modern banking software will typically result in a rejection.
• Retired or reassigned BLZ codes: Deutsche Bundesbank publishes periodic updates to the BLZ directory. Banks merge, close, or reroute. A BLZ that was valid years ago may now be inactive or reassigned. Always verify against the current Bundesbank directory before using an unfamiliar code.
• Leading zeros are significant: BLZ codes always have exactly 8 digits. A leading zero must not be dropped. For example, 08000000 is a different code from 80000000.
• Confusing BLZ with Kontonummer: The BLZ identifies the bank or branch; the Kontonummer (account number, up to 10 digits) identifies your specific account. Both are required for domestic payments and both are embedded within your IBAN.
• International transfers: Do not use a BLZ code for international wire transfers outside SEPA. Use the full IBAN and the bank's SWIFT / BIC code.
• Multiple BLZ codes per bank: Large German banks may have dozens of BLZ codes — one per branch or regional processing centre. Always use the BLZ that corresponds to the specific branch where the account is held, not the bank's head office BLZ.

Equivalent Codes in Other Countries

• United Kingdom / Ireland: Sort code — 6-digit domestic branch identifier.
• United States: ABA Routing Transit Number (RTN) — 9-digit code.
• Australia: BSB (Bank State Branch) — 6-digit code.
• France: Code Banque (5 digits) + Code Guichet (5 digits) — embedded in the French RIB and IBAN.
• International: SWIFT / BIC — used globally for cross-border interbank identification.