IBAN cálculo rápido
Use this tool to calculate IBAN check digits from a country code + BBAN, or validate a complete IBAN instantly.
1) Calculate IBAN
Tip: spaces and dashes are ignored automatically.
2) Validate IBAN
What does “iban calculo” mean?
“IBAN cálculo” usually refers to computing or checking the International Bank Account Number. IBAN is a standardized account format used across many countries to reduce transfer errors and improve payment routing. A valid IBAN includes: a country code, two check digits, and a BBAN (Basic Bank Account Number).
If you are making international or SEPA transfers, knowing how IBAN calculation works helps you spot typos before money is sent. The two check digits are mathematically generated using a MOD-97 algorithm, which makes random mistakes easy to detect.
How IBAN calculation works (MOD-97)
Step 1: Build a temporary string
Start from your BBAN and country code. Move the country code and check digits to the end, using 00 as temporary check digits:
- Temporary form: BBAN + CountryCode + 00
Step 2: Convert letters to numbers
Replace letters with values A=10, B=11, ..., Z=35. Digits stay as they are. This creates a very long integer string.
Step 3: Compute remainder
Compute the number modulo 97. Then calculate: Check Digits = 98 - remainder. If result is one digit, pad with a leading zero.
Step 4: Build final IBAN
Final format: CountryCode + CheckDigits + BBAN. A final validation should satisfy: full IBAN transformed number modulo 97 equals 1.
Example of IBAN cálculo
Suppose you have a Spanish BBAN: 21000418450200051332 and country code ES. Running the algorithm returns check digits 91, so the complete IBAN is: ES91 2100 0418 4502 0005 1332.
This is exactly what the calculator above does in your browser, with no server required.
Common mistakes and how to avoid them
- Using the wrong country code (for example, ES vs. PT).
- Confusing letter O with digit 0 in alphanumeric BBAN formats.
- Copy/paste errors caused by hidden spaces or dashes.
- Assuming all countries use the same IBAN length.
- Skipping validation before submitting a transfer.
Why IBAN validation is important
IBAN validation reduces failed payments, bank charges, and delays. Even when your banking app validates automatically, checking in advance can save time during payroll, supplier payments, and cross-border transfers.
Keep in mind: an IBAN can be mathematically valid but still belong to a closed or incorrect account. Validation confirms structure and check digits, not account ownership.
Quick FAQ
Is IBAN the same as SWIFT/BIC?
No. IBAN identifies the account. SWIFT/BIC identifies the bank institution.
Can I calculate IBAN manually?
Yes, with the MOD-97 process. But for speed and fewer mistakes, a calculator is better.
Does every country use IBAN?
No. Many countries do, but not all. Always check destination country payment rules.
Final note
If you regularly work with transfers, bookmark this iban calculo page. It helps you generate check digits, verify complete IBANs, and understand the logic behind secure account formatting.