Support Guides
Learn how IBAN, routing numbers, and card validation work — clearly and simply.
Everything you need to know about International Bank Account Numbers — structure, validation, country formats, and how they compare to SWIFT and card numbers.
What Is an IBAN?
Understand what an IBAN is, what each part means, and when people need one for real payments.
Read guide →
How IBAN Validation Works
A practical breakdown of country checks, fixed lengths, and the MOD-97 checksum used in IBAN validation.
Read guide →
IBAN Format by Country
Compare IBAN lengths, example structures, and country-specific differences across major IBAN markets.
Read guide →
IBAN vs SWIFT/BIC
See the difference between IBAN and SWIFT/BIC, what each identifier is for, and when transfers need both.
Read guide →
IBAN vs Card Number
Understand why IBAN and card numbers belong to different payment systems and should never be used interchangeably.
Read guide →
Common IBAN Errors
See the most frequent reasons an IBAN fails validation and how to prevent bad banking data from entering your workflow.
Read guide →
How payment card numbers are structured, validated, and used — from BIN prefixes and brand detection to the Luhn algorithm and CVV.
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.
Read guide →
How Card Validation Works
See how card validators check patterns, lengths, and the Luhn checksum before any real payment attempt happens.
Read guide →
Card Number Format by Network
Compare card number lengths, starting digits, and format differences across major payment networks.
Read guide →
What Is the Luhn Algorithm?
A plain-language guide to the Luhn checksum, how it detects common typing mistakes, and where it is used.
Read guide →
Card Number vs IBAN
Compare card numbers and IBANs by payment rail, data sensitivity, and the situations where each one is actually needed.
Read guide →
Common Card Number Errors
The most common reasons card numbers fail validation and how better form design reduces preventable payment input mistakes.
Read guide →
ABA routing numbers, account number formats, ACH payments, and wire transfers — the complete reference for US banking and fintech.
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.
Read guide →
How 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.
Read guide →
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.
Read guide →
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.
Read guide →
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.
Read guide →
IBAN vs ABA Routing Number — International vs US Bank Transfers
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.
Read guide →
Put the knowledge into practice — run a live format check on any IBAN, card number, or US routing number.
IBAN Validator
Check IBAN structure, country code, and MOD-97 checksum instantly.
Card Validator
Validate card number format and detect the brand via Luhn algorithm and BIN prefix.
Routing Number Validator
Check routing number format, verify ABA checksum, and identify the bank instantly.