How the CLABE Validation Works

Mexico’s CLABE (Clave Bancaria Estandarizada) is a unique 18-digit code that identifies every bank account in the country. Think of it like a routing number and account number combined into one standardized format that all Mexican banks use.

The validator checks three things. First, it confirms you’ve entered exactly 18 digits (no more, no less). Second, it breaks down the number to identify which bank it belongs to using the first three digits. Third, and most importantly, it runs a mathematical check digit algorithm to verify the entire number is mathematically valid.

This isn’t just pattern matching. The algorithm catches typos, transposed digits, and fake numbers. If someone gives you a CLABE that passes validation, you can be confident it’s a real account number format, though it doesn’t guarantee the account is active or belongs to the person claiming it.

What Each Part of Your CLABE Means

A CLABE number isn’t random. It’s structured into three segments, and understanding what each part does helps you spot errors faster.

Digits 1-3: Bank Code
These identify which Mexican bank holds the account. For example, 002 is Banamex, 012 is BBVA Mexico, 014 is Santander. There are over 150 registered bank codes in Mexico’s banking system. If these three digits don’t match a known bank, the CLABE is invalid immediately.

Digits 4-6: Branch Code
This identifies the specific branch where the account was originally opened. Some digital banks use 000 or 001 for all accounts since they don’t have physical branches. This segment doesn’t affect validation but helps the bank route transfers correctly.

Digits 7-17: Account Number
These 11 digits are the actual account number. Banks assign these sequentially or use their own internal systems. This is the unique identifier for the account holder within that specific bank and branch.

Digit 18: Check Digit
The final digit is calculated from the previous 17 using a specific formula. It’s not part of the account number. It exists purely to verify that the entire CLABE wasn’t mistyped or corrupted. If someone changes even one digit in the CLABE, the check digit won’t match anymore.

Common Mistakes People Make

Using a Debit Card Number Instead
Your 16-digit card number is NOT your CLABE. Card numbers are for purchases. CLABEs are for bank transfers. They’re completely different systems. If you enter a card number, it’ll fail immediately because it’s only 16 digits.

Mixing Up Account Number and CLABE
Some banks show a shorter account number (10 or 11 digits) on statements. That’s not your full CLABE. You need the complete 18-digit number. Check your online banking portal or ask your bank directly for the full CLABE.

Adding Spaces or Hyphens
CLABEs are written as 18 continuous digits. No spaces, no dashes, no formatting. If you copy it from a PDF or website that has visual formatting, remove all spaces before pasting.

Confusing CLABE with SWIFT or IBAN
CLABE is only for domestic Mexican transfers. If you’re sending money internationally TO Mexico, you might need a SWIFT code instead. If you’re sending FROM Mexico internationally, you still use your CLABE but the receiving country might need different codes.

When CLABE Validation Isn’t Enough

Here’s what this tool does NOT confirm. It doesn’t verify the account is active, that it belongs to a specific person, or that it can receive the type of transfer you’re sending. A mathematically valid CLABE could still belong to a closed account or someone you don’t intend to pay.

Before sending large amounts, double-check the account holder’s name with your bank. Many Mexican banks now show the recipient’s name before you confirm a transfer. This is your last line of defense against sending money to the wrong person.

Also, some banks have limits on who can receive transfers. Savings accounts, student accounts, or certain promotional accounts might reject incoming SPEI transfers even if the CLABE is valid. If a transfer fails repeatedly with a correct CLABE, ask the recipient to confirm their account can receive transfers.

Who Needs to Validate CLABEs?

Freelancers Getting Paid
If you’re receiving payment from a Mexican client, send them your CLABE and validate it yourself first. A single wrong digit means payment fails and you wait days for it to bounce back.

Anyone Paying Rent or Services
Landlords, utility companies, and service providers in Mexico often require SPEI transfers using CLABE. Validate before the first payment to avoid late fees from failed transfers.

E-commerce and Marketplace Sellers
If you sell on Mexican platforms and receive payouts via bank transfer, verify your CLABE is registered correctly. One typo in your account settings means payments pile up in limbo.

Employers Doing Payroll
Companies paying employees via direct deposit need each employee’s correct CLABE. Validating them upfront prevents payroll errors that frustrate employees and create accounting headaches.

International Senders
If you’re outside Mexico sending money to someone there, ask them to validate their CLABE before you initiate the transfer. International fees make mistakes expensive.

What to Do If Your CLABE Fails Validation

Check for Typos First
Look at each digit carefully. Did you mix up 0 and O? Is there an extra space? Did you accidentally include a letter? The most common errors are simple transcription mistakes.

Get It Directly from Your Bank
Don’t rely on old statements or memory. Log into your online banking or mobile app and copy the CLABE directly from there. Every Mexican bank displays it clearly in account details.

Call Your Bank If Unsure
If the CLABE from your bank’s system fails validation, something is wrong. Contact customer service immediately. Either their system has an error (rare but possible) or you’re looking at the wrong number.

Don’t Use a Failed CLABE
Never try to send money using a CLABE that doesn’t validate. It will fail. Even if it somehow goes through initially, it could bounce back days later, tying up your money and triggering fees.

CLABE vs Other Mexican Bank Codes

Mexico uses several different banking codes depending on what you’re doing. Here’s how CLABE fits into the bigger picture.

CLABE (18 digits): For domestic bank transfers within Mexico using SPEI system. This is what you need for most person-to-person and business payments inside Mexico.

Debit/Credit Card Number (16 digits): For purchases and ATM withdrawals. Cannot be used for bank transfers. Completely separate from CLABE.

Account Number (10-11 digits): Your internal bank account number. Part of the CLABE but not usable alone for transfers from other banks.

SWIFT/BIC Code: For international transfers coming into Mexico. Used alongside CLABE when receiving money from abroad.

Bank Code (3 digits): The first three digits of a CLABE. Sometimes requested separately for certain systems but always part of the full CLABE.

How Fast Are CLABE Transfers?

SPEI transfers using CLABE are almost instant in Mexico. The system was designed for real-time payments, and most transfers complete within seconds during banking hours.

During business hours (roughly 7 AM to 7 PM on weekdays), transfers usually arrive in under 60 seconds. Outside these hours or on weekends, they might take a few minutes but still process the same day. Banks can’t hold SPEI transfers overnight like they do with checks.

If a CLABE transfer doesn’t arrive within 15 minutes, something went wrong. Either the CLABE was invalid (though it should have been rejected immediately), the receiving account can’t accept transfers, or there’s a technical issue. Contact your bank right away.

Sample CLABE Validation Examples

Frequently Asked Questions