— text & data —
LiveBulk-check IBANs
Check a whole list of IBANs for validity at once.
runs entirely in your browser
What this tool does and doesn't do
Mathematical validation, structure, length per country code, and MOD-97 checksum. For Dutch IBANs the bank code is identified. What this tool does NOT do: verify that the account exists, is active, or belongs to the right name-holder. That requires a SurePay / IBAN-Name Check service, which is paid API access.
Frequently asked questions
Are my IBANs stored or sent anywhere?
No. All validation happens in your browser, no server call, no log. Paste 500 IBANs from your donor database, close the tab, and the data is gone. No copy stays with Plainjar.
What does this tool actually check?
The structural requirements from ISO 13616: length per country code, allowed characters only, and the MOD-97 checksum. For Dutch IBANs, the bank code (4 letters after NLxx) is looked up in a built-in table. The tool does NOT verify whether the account actually exists, is active, or belongs to the correct name-holder, that requires a paid IBAN-Name Check service like SurePay.
Does this work for foreign IBANs?
Yes, all SEPA countries plus every other country issuing official IBANs are validated on structure and checksum. The bank-name mapping is for Dutch IBANs only (NL...), they have a fixed 4-letter bank code at positions 5-8. For other countries only 'valid/invalid' is shown.
How many IBANs can I check at once?
No artificial limit. The first 200 are shown in the table for responsiveness; the complete list is always in the CSV download. Validating 10,000 IBANs takes under a second on a normal device.
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Text processing happens entirely in your browser. What you paste stays on your device.