Support Guide
A complete comparison of IBANs and ABA routing numbers — what each identifies, where each is used, and how to determine which one you need for a payment.
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Bank Details
Paste full bank details — routing number (ABA) and account will be detected automatically.
This tool validates format only. It does not verify whether the bank account exists or can receive payments.
An IBAN (International Bank Account Number) is a standardized account identifier used across Europe, the Middle East, and many other regions. An IBAN encodes the country code, check digits, bank code, branch code (in some countries), and account number — all in a single string of up to 34 alphanumeric characters. The MOD-97 checksum covers the entire IBAN, providing strong error detection.
An ABA routing number identifies only the bank or bank branch, not the individual account. In the US system, you always need both a routing number (9 digits) AND a separate account number (4–17 digits) to uniquely identify a bank account. There is no single combined identifier equivalent to an IBAN in the US domestic payment system.
Think of IBAN as a complete postal address and the routing number as just the postal code — the routing number gets you to the right bank, but you still need the account number to reach the specific account.
IBAN is mandatory for bank transfers within SEPA (Single Euro Payments Area), which covers all 27 EU countries plus Iceland, Liechtenstein, Norway, Switzerland, the UK, Monaco, San Marino, and Andorra. Many other countries also use IBAN.
ABA routing numbers are used exclusively within the United States for domestic ACH transfers and domestic wire transfers. The US banking system does not use IBAN for domestic transfers.
For international transfers involving the US: if you are sending money from the US to Europe, you will need the recipient's IBAN and their bank's SWIFT BIC code. If a European is sending money to a US account, they will typically need the ABA routing number, the account number, and the bank's SWIFT BIC.
Format: IBAN is up to 34 alphanumeric characters starting with a 2-letter country code. An ABA routing number is exactly 9 digits. A US account number is 4–17 digits, separate from the routing number.
Error detection: IBAN uses a MOD-97 checksum over the entire combined number. ABA uses a 3-7-1 weighted checksum over 9 digits. US account numbers have no standardized checksum.
What it identifies: IBAN identifies a specific bank account globally. ABA routing number identifies only the bank — you need the account number separately. Geographic scope: IBAN covers 80+ countries; ABA routing numbers are US-only.
No. The United States does not participate in the IBAN standard. For international transfers to a US bank account, the sender typically needs the ABA routing number (or SWIFT BIC for international wires) and the account number.
A SWIFT BIC identifies a bank internationally for cross-border wire transfers. An ABA routing number identifies a bank domestically within the US. For international wires to or from the US, the SWIFT BIC is used — not the ABA routing number.
The US banking system predates the IBAN standard by decades and has never adopted it. The sheer number of US financial institutions and the cost of transition have made IBAN adoption impractical. The US Treasury has studied it but no mandatory implementation has been announced.
This tool checks format only. It validates routing number structure and ABA checksum, but does not confirm that a bank account exists, is active, belongs to a person, or can receive payments. It does not perform financial, identity, or bank verification.
What Is an ABA Routing Number?
Everything you need to know about ABA routing transit numbers — their structure, history, how they are assigned, and how they differ from account numbers.
ACH vs Wire Transfer — What's the Difference?
A practical comparison of ACH and wire transfers — how each works, when to use which, typical costs, settlement times, and routing number requirements.
Routing Number vs Account Number — What's the Difference?
A clear explanation of what routing numbers and account numbers do, how they work together, and how to keep your account number secure.
Use the main validator when you need a fast structural check. Use support guides when you need deeper context, implementation detail, or troubleshooting help.
Open Routing Number ValidatorHow to Read a US Check — Finding Routing and Account Numbers
A step-by-step guide to the MICR line on the bottom of a US check, including where to find the routing number, account number, and check number.
Common Routing Number Errors and How to Fix Them
The most frequent mistakes people make with ABA routing numbers — wrong length, transposed digits, wrong routing number type, and how each error affects your transfer.