How to issue Luxembourg IBANs
A Luxembourg IBAN is 20 characters — LU, two check digits, a three-digit bank code and a thirteen-character account number — and once you hold a CSSF licence, issuing your own range is a build project, not a licensing one. For an EMI or payment institution passporting across Europe, LU-prefixed accounts signal a Grand Duchy footprint and plug straight into SEPA. This piece covers the LU IBAN structure, how the bank code is allocated, the BIC mapping, the SEPA scheme obligations that come with issuing, and what reporting switches on once accounts go live.
1. The Luxembourg IBAN format
Luxembourg follows the ISO 13616 / EBS 204 standard with a fixed length of 20 alphanumeric characters:
- Positions 1–2: the country code
LU(ISO 3166) - Positions 3–4: two check digits computed under ISO 7064 (mod-97-10)
- Positions 5–7: the three-digit bank code identifying the institution
- Positions 8–20: a thirteen-character account identifier, freely assigned by the institution (A–Z, 0–9)
A worked example: LU28 0019 4006 4475 0000. Print form groups the string in fours; electronic form is unbroken. Because the account identifier is only 13 characters, capacity planning matters at scale — design the numbering scheme before you issue the first account.
2. How the bank code is allocated
The three-digit bank code is drawn from Luxembourg’s national IBAN/BIC register, coordinated with the supervisory authorities. You do not invent it: an institution authorised by the CSSF is allocated a code, which then appears in positions 5–7 of every IBAN it issues and maps to its BIC. Until the code is allocated, no LU IBAN can be minted, so sequence the request into the post-authorisation runway rather than leaving it to go-live week.
3. The BIC mapping
For a directly-connected institution the BIC is your own; some issuers reach SEPA through a sponsor’s infrastructure, in which case the routing BIC and the account-holding arrangement need to be crystal clear in the customer-facing IBAN and in reconciliation.
4. What issuing IBANs commits you to
Issuing LU IBANs means operating as a SEPA-reachable payment service provider. That brings a scheme rulebook stack:
- SEPA Credit Transfer (SCT) — the baseline euro credit-transfer scheme
- SEPA Instant Credit Transfer (SCT Inst) — now effectively mandatory under the Instant Payments Regulation, together with verification of payee on outbound transfers
- SEPA Direct Debit (SDD) — Core and B2B, where your product collects
- IBAN-discrimination rules under Regulation (EU) 260/2012 — a payer or payee anywhere in the EU may use your LU IBAN and cannot be refused for its country prefix
5. What reporting switches on once accounts are live
- Ongoing CSSF prudential and statistical returns for the licensed institution
- AML transaction monitoring on the accounts, with suspicious-activity reporting to the CRF via goAML
- CESOP cross-border payment reporting once the per-payee quarterly threshold is crossed
- Instant-payments statistical and fraud-data obligations under the IPR
6. LU IBANs against the other core formats
| Country | IBAN length | Bank-code digits | Distinctive point |
|---|---|---|---|
| Luxembourg (LU) | 20 | 3 | Short 13-char account field — plan capacity early |
| Germany (DE) | 22 | 8 (Bankleitzahl) | SEPA direct debit non-negotiable |
| Italy (IT) | 27 | 5 (ABI) + 5 (CAB) | Includes a national check character (CIN) |
| Netherlands (NL) | 18 | 4 (letters) | Bank code is alphabetic |
| France (FR) | 27 | 5 | Includes an RIB key |
7. FAQ
How long is a Luxembourg IBAN?
Exactly 20 characters: LU, two check digits, a three-digit bank code, and a thirteen-character account identifier.
Do I need a Luxembourg licence to issue LU IBANs?
Yes. LU IBANs are issued by a payment or e-money institution authorised by the CSSF (or a bank). See our EMI licence in Luxembourg piece.
Where does the three-digit bank code come from?
It is allocated to your institution from Luxembourg’s national IBAN/BIC register, in coordination with the supervisory authorities, and maps to your BIC. You cannot self-assign it.
Can a customer elsewhere in the EU use my LU IBAN?
Yes — and they cannot be refused for the country prefix. IBAN-discrimination rules under Regulation (EU) 260/2012 make any SEPA IBAN reachable across the euro area.
Is SEPA Instant mandatory for LU IBANs?
Effectively yes. The Instant Payments Regulation phases in mandatory send and receive of euro instant transfers, with verification of payee on outbound payments.
8. What to do, today
- Request the bank-code allocation as soon as the CSSF authorisation is in sight — don’t leave it to go-live week.
- Confirm the IBAN-to-BIC mapping and SEPA reachability before the first outbound transfer.
- Design the 13-character account numbering scheme for scale from the outset.
- Wire SCT Inst and verification of payee in from day one, not as a later retrofit.
Related: EMI licence in Luxembourg · How to issue German IBANs · Verification of payee under the IPR
