Support Guide
Compare card numbers and IBANs by payment rail, data sensitivity, and the situations where each one is actually needed.
You do not need to leave this guide to run a structural check. Use the same validator here, then continue reading if you need more context.
A card number belongs in checkout, subscription billing, tokenization, and merchant payment flows. An IBAN belongs in account payouts, salary payments, direct debits, and transfer instructions.
The user should never have to guess which one is needed from the field label alone.
Card data is generally more sensitive in operational handling because it interacts with card-network payment credentials and related security controls. IBAN data is still sensitive, but it is not handled in the same way.
Clear guidance on the page reduces misuse and builds trust.
Use direct labels, inline examples, and immediate validation. Pair that with short explanatory copy so users know whether they are entering transfer details or card credentials.
This is especially important in fintech products where the same user may both receive payouts and make card payments.
| IBAN | Card | |
|---|---|---|
| What it identifies | A bank account | A payment card product |
| Length | 15–34 characters | 15 digits (Amex) or 16 digits (Visa/MC) |
| Contains letters | Yes (country code + bank codes) | No — digits only |
| Has expiry date | No — account is open-ended | Yes — MM/YY printed on card |
| Has CVV / CVC | No | Yes — 3 or 4 digit security code |
| Payment rail | SEPA, SWIFT, bank transfer | Visa, Mastercard, Amex networks |
| Use case | Wire transfers, payroll, direct debit | Retail purchases, online checkout |
| Safe to share | Yes, with trusted payees | Number yes; CVV never share |
| Validated by | Mod-97 checksum (ISO 13616) | Luhn algorithm |
No. Payouts to bank accounts require account details such as an IBAN.
No. Card checkouts need card-specific payment credentials.
This tool checks format only. It validates structure and checksum, but does not confirm that a card exists, is active, has funds, is not blocked, or can be charged. It does not perform payment authorization or issuer verification.
IBAN vs Card Number
Understand why IBAN and card numbers belong to different payment systems and should never be used interchangeably.
What Is a Card Number?
Learn what a card number represents, how BIN/IIN ranges work, and how it differs from CVV and expiry details.
What Is an IBAN?
Understand what an IBAN is, what each part means, and when people need one for real payments.
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 CardWhat Is a Card Number?
Learn what a card number represents, how BIN/IIN ranges work, and how it differs from CVV and expiry details.
How Card Validation Works
See how card validators check patterns, lengths, and the Luhn checksum before any real payment attempt happens.
Card Number Format by Network
Compare card number lengths, starting digits, and format differences across major payment networks.
What Is the Luhn Algorithm?
A plain-language guide to the Luhn checksum, how it detects common typing mistakes, and where it is used.
Common Card Number Errors
The most common reasons card numbers fail validation and how better form design reduces preventable payment input mistakes.