Banxico describes the CLABE as a unique number assigned to each bank account, and it is what another institution needs to pay into one. A cousin in Puebla hands it to a US transfer service, an employer uses it to deposit wages and the phone company uses it to collect a monthly bill by direct debit. This entry takes the 18 digits apart, runs the check digit on a made-up number, lists where to look one up and sets the CLABE beside the IBAN, SWIFT code and card number it gets mixed up with. Sending money abroad more broadly is covered in the money transfer hub.
What do the 18 digits of a CLABE stand for?
Read left to right, a CLABE gives the bank, then the plaza, then the account, and closes with one digit that checks the other seventeen. Banxico and the ABM, Mexico's bankers' association, define the four parts this way:
| Digits | Part | Where the code comes from |
|---|---|---|
| 1 to 3 | Bank code (código de banco) | The number the ABM gives each credit institution |
| 4 to 6 | Plaza code (código de plaza) | The city or region of the account, from the plaza codes defined for check processing |
| 7 to 17 | Account (número de cuenta) | Whatever reference the bank uses internally to tell its customers' accounts apart |
| 18 | Check digit (dígito de control) | Worked out from digits 1 to 17 with a fixed formula |
The bank code tells you at a glance which institution holds the account. In the code catalog Banamex publishes for business clients, 012 is Bancomer, now BBVA México, 014 is Santander and 072 is Banco Mercantil del Norte, better known as Banorte. Banxico's public list of SPEI institutions shows the same three digits at the end of their five-digit codes: 40012, 40014 and 40072.
The three plaza digits are often called a branch code, yet the official definition is a place: the city or region where the customer holds the account. In the plaza catalog on Banamex's help pages, 180 covers Mexico City along with nearby municipalities such as Naucalpan and Ecatepec, 320 covers Guadalajara and Zapopan, and 580 covers Monterrey and San Pedro Garza García.
The 11 account digits carry the information each bank uses to identify a customer's account, and CONDUSEF, the financial consumer agency, calls the CLABE an additional reference that does not replace the account number or the debit card number. That uniqueness is the point of the standard: money sent by interbank transfer, payroll deposit or direct debit is applied only to the account the customer gave. The SPEI guide explains how the payment system that reads these numbers works, from timing to receipts.
How is a CLABE check digit calculated?
The check digit comes from a weighted sum of the first 17 digits, cut down to a single digit with modulo 10 arithmetic. Banamex sets out the method in its help pages for business clients: weights of 3, 7 and 1 repeat from left to right, and only the units digit of each product is kept.
The final mod 10 turns a result of 10 into 0. Keeping only the units digit of each product is a shortcut for mental arithmetic: adding the full products gives a total with the same last digit, so the answer never changes.
Worked example: Checking a made-up CLABE, three digits at a time
The number below is invented: no institution in Banxico's list of SPEI institutions has a code ending in 000, and plaza 320 is Guadalajara's. Because the weights repeat every three digits, the bank code, the plaza and each run of three account digits all get the same 3, 7, 1 treatment.
| Part | Digits | Weights | Products | Units digits | Subtotal |
|---|---|---|---|---|---|
| Bank code | 0, 0, 0 | 3, 7, 1 | 0, 0, 0 | 0, 0, 0 | 0 |
| Plaza | 3, 2, 0 | 3, 7, 1 | 9, 14, 0 | 9, 4, 0 | 13 |
| Account, positions 7 to 9 | 9, 8, 7 | 3, 7, 1 | 27, 56, 7 | 7, 6, 7 | 20 |
| Account, positions 10 to 12 | 6, 5, 4 | 3, 7, 1 | 18, 35, 4 | 8, 5, 4 | 17 |
| Account, positions 13 to 15 | 3, 2, 1 | 3, 7, 1 | 9, 14, 1 | 9, 4, 1 | 14 |
| Account, positions 16 and 17 | 0, 1 | 3, 7 | 0, 7 | 0, 7 | 7 |
- The subtotals add up to 71, whose last digit is 1, and 10 − 1 = 9. The complete made-up CLABE is 000320987654321019.
- Adding the full products instead gives 0 + 23 + 90 + 57 + 24 + 7 = 201, which also ends in 1.
- Now suppose the eighth digit is mistyped as 3 rather than 8. Its product becomes 21, the units digit falls from 6 to 1 and the total drops to 66, so the check digit ought to be 4. The 9 at the end no longer fits, so the number fails the integrity check that, according to the ABM, both the sending and the receiving bank run.
Because 3, 7 and 1 share no factor with 10, changing any one digit always changes the result, so a single slip can never pass. A pass shows only that the 18 digits agree with each other. It says nothing about whether the account is open, whose name it is in or who supplied the number, which is why a scammer's genuine CLABE passes the test as easily as a relative's.
Where can you find a CLABE?
CONDUSEF lists three places to find a CLABE: the account statement, online or app banking, and the bank itself. In practice that means:
- The banking app. BBVA México and Banamex, for example, show it in each account's details next to the account number, and both let the holder copy it instead of retyping it.
- The statement. It is printed on the account statement, the estado de cuenta.
- The bank. BBVA México, for instance, gives it over the phone once the caller keys in card details, and at a branch to a customer who brings ID and the card.
- An earlier receipt. The CEP, Banxico's electronic receipt for a SPEI payment, shows the account holder's name and the CLABE or card number involved, so the receipt for a transfer that arrived is a record of a number that worked.
A CLABE is safe to hand out for receiving money; banks tell customers it is the number others need to pay them, and that the card PIN and the CVV are what must stay private. When sending from the US, have the recipient copy the CLABE from the app into a message rather than read it aloud, enter it in the provider's form without spaces or dashes, and make sure the first three digits match the bank the recipient named. The guide to sending money from the US to Mexico covers the name and ID details a deposit also needs, a first transfer can bring the identity checks described under know your customer, and the money transfer cost calculator compares what different ways to send will cost.
How is a CLABE different from an IBAN, SWIFT code or card number?
A CLABE pins down one account inside Mexico; the numbers it is confused with identify a card, a bank or an account in another country's format.
| Number | Format | What it identifies | Where it is used |
|---|---|---|---|
| CLABE | 18 digits | One account at a Mexican institution | SPEI transfers, payroll, direct debits and the account field of wires to Mexico |
| Bank account number | Set by each bank | The account within its own bank | Alongside the CLABE, which does not replace it |
| Debit card number | 16 digits | A card linked to an account | Card payments; SPEI also accepts it as a destination |
| Dimo mobile number | A phone number | The single account its owner linked to it | Transfers from banking apps that offer Dimo |
| SWIFT code (BIC) | 8 or 11 characters | A bank, not an account | International wires, next to the CLABE |
| IBAN | Up to 34 characters | An account in a country that uses IBANs | Not used in Mexico |
| ABA routing number | 9 digits | A US bank | US payments; Mexican banks do not use it |
As of November 2, 2026, Mexico is not one of the 89 countries and territories in Swift's IBAN registry, so a European bank that asks for an IBAN should get the CLABE in the account field. A wire from abroad pairs the CLABE, which finds the account, with the receiving bank's SWIFT code, which finds the bank, and it may pass through correspondent banks on the way. The guides to IBAN numbers, SWIFT codes and routing numbers and SWIFT codes cover those formats.
Banxico's Mi SPEI page lists 16-digit debit card, e-money card and credit card numbers as alternatives to the 18-digit CLABE, which helps a recipient who cannot find the CLABE. The card number belongs to the card, though, while the CLABE belongs to the account. Dimo lets a holder attach one mobile number to one account through the bank's app, after which payers can use the phone number in its place.
What happens if money goes to the wrong CLABE?
Inside Mexico, a SPEI payment that has been settled and credited is final, so a payment to a mistaken but valid CLABE cannot simply be reversed. Banxico cites Rule 18 of its Circular 14/2017, under which credited transfers are firm and irrevocable, and suggests taking the receipts to the bank's customer service or its specialized complaints unit, the Unidad Especializada, and then to CONDUSEF if the bank does not resolve the case.
For money sent from the US, the federal remittance rule normally makes the provider fix errors, but it carves out wrong account numbers supplied by the sender. Under 12 CFR 1005.33(h), the provider is off the hook only if it meets all five conditions:
- it can show that the sender gave it the wrong number;
- when the error was in the bank identifier, it used reasonably available means to check that the identifier matched the bank's name;
- before the sender paid, it warned that a wrong number could mean losing the transfer amount;
- the wrong number caused the deposit into someone else's account; and
- it promptly made reasonable efforts to recover the money.
If the provider falls short on any of them, the misdirected payment counts as an error that it has to put right. A CLABE is both kinds of identifier at once, because its first three digits name the institution. The guide to remittance transfer rights explains how to report an error, and the guide to money transfer scams covers fraudsters who send new account details just before a payment is due.