What is a CLABE?
A CLABE (Clave Bancaria Estandarizada, or standardized bank code) is the 18-digit number that identifies a specific bank account in Mexico. Banco de México describes it as "a unique and non-repeatable number assigned to each bank account", and its use has been mandatory for interbank electronic transfers since June 1, 2004. It is often called a "CLABE interbancaria" or "cuenta CLABE."
Because the first three digits identify the bank, a CLABE alone is enough to route a payment. Payout APIs that deliver over SPEI, including Due's, take the CLABE as the recipient account.
Key facts about the CLABE:
- Full name: Clave Bancaria Estandarizada (standardized bank code)
- Also called: CLABE interbancaria, cuenta CLABE
- Length: 18 digits
- Structure: 3-digit bank code, 3-digit plaza code, 11-digit account number, and 1 check digit
- Mandatory since: June 1, 2004, for interbank electronic transfers
- Identifies the bank: Yes, through the first three digits
- Check digit method: repeating weights of 3, 7, 1, modulo 10
- Main payment rail: SPEI, operated by Banco de México
What do the 18 digits of a CLABE mean?
Each block of a CLABE carries a different piece of routing information. Per Banco de México, the 18 digits break down as follows:
- Bank code (digits 1 to 3): identifies the financial institution holding the account
- Plaza code (digits 4 to 6): identifies the city or region where the account was opened
- Account number (digits 7 to 17): the 11-digit number the bank uses to identify the individual account
- Check digit (digit 18): validates the 17 digits before it
This is the key operational difference from identifiers like the Nigerian NUBAN, where the bank has to be selected separately. With a CLABE, the sender never chooses a bank from a list, so there is no risk of pairing a correct account number with the wrong bank.
How is the CLABE check digit calculated?
The check digit is a weighted modulo-10 calculation over the first 17 digits. Banco de México sets out the method in Annex 4 of its rules for electronic payment fund institutions, the same rules that require fintech e-money issuers to assign a CLABE to each customer account:
- Multiply each of the first 17 digits by the repeating weights 3, 7, 1, 3, 7, 1, and so on
- Keep only the last digit of each product (modulo 10) and add them together
- Take that sum modulo 10 and subtract it from 10
- If the result is 10, the check digit is 0
Banco de México's worked example uses the first 17 digits 00218003224094670. The products modulo 10 are 0, 0, 2, 3, 6, 0, 0, 1, 2, 6, 8, 0, 7, 8, 6, 1, 0, which add up to 50.
Because 50 modulo 10 is 0, step 3 gives 10, so the check digit is 0 and the full CLABE is 002180032240946700.
Does a valid CLABE mean the account exists?
No. A correct check digit only proves the 18 digits are internally consistent: it catches typos, but it cannot confirm that the account is open or who owns it.
SPEI handles the first problem at the system level: under Banco de México's SPEI rules (Circular 14/2017), the receiving institution must return a transfer addressed to a nonexistent account within 60 seconds of the settlement notice.
The second problem is harder, because a valid CLABE that belongs to the wrong person will be credited like any other. Confirming account ownership before a first payout, for example with a penny test, closes that gap.
Can you send a SPEI transfer without a CLABE?
Sometimes: Banco de México says SPEI transfers can be addressed using "the Standardized Bank Code (CLABE) for the account (18 digits), the debit card number (16 digits) or the cell-phone number (10 digits)".
Card and phone numbers point to an underlying account, while the CLABE identifies the account itself. The Mexican Bankers Association ties the CLABE specifically to payroll, direct debits, and interbank transfers, which is why payout APIs ask for it.
SPEI runs 24 hours a day, 365 days a year and settles transfers in central bank money. It processed 5.34 billion transfers in 2024, up from 3.82 billion in 2023, according to Banco de México.
Every SPEI transfer also carries a tracking key (clave de rastreo), and Banco de México issues an electronic payment receipt (CEP) confirming the credit to the beneficiary's account. Together they give operators a reference for payment reconciliation and proof of delivery.
How does a CLABE compare to an IBAN or NUBAN?
All three identify where a payment should land, but they encode different information:
Mexico does not use IBANs. International transfers into Mexico typically identify the beneficiary account by its CLABE, whether they arrive as a SWIFT wire or are paid out locally over SPEI.
How do you send and receive MXN with a CLABE through Due?
Due connects to SPEI in both directions. The MXN capabilities are:
- SPEI payouts: instant MXN transfers to any CLABE
- SPEI pay-ins: instant MXN collections
- MXN virtual accounts: each one is issued with its own CLABE, so counterparties in Mexico can pay in with a standard SPEI transfer
Due's recipient schemas include a dedicated CLABE field type for Mexican accounts. For corridor costs, providers, and timing, see Due's guide to sending money to Mexico.
Book a call if you want to learn how you can set up MXN payouts and collections with Due
