SPEI carries pesos between bank accounts all over Mexico, and it is often the last leg of a transfer from the US that ends in an account. The sections below cover who operates SPEI, how the 18-digit CLABE is put together and how to check one by hand, how quickly a payment must land depending on its size and the hour, how to download Banxico's CEP receipt, where CoDi and Dimo fit, how dollars reach a CLABE and how a deposit compares with cash pickup or a card payout. The money transfer hub covers the rest of sending money abroad.
What is SPEI and who runs it?
SPEI, the Sistema de Pagos Electrónicos Interbancarios, is the real-time payment system that Banco de México (Banxico) regulates and operates, in service since August 2004. It handles small and large payments alike, runs 24 hours a day on every day of the year, and any regulated financial institution can apply to take part. Banxico describes each settled transfer as final and irrevocable, and the system's operating day rolls over at 6 p.m., which matters for the timing rules below.
Banxico calls SPEI the most important payment system in the country, and the numbers back that up. In 2025 it processed 7,308.1 million transfers worth MXN 591.8 trillion, about 16.8 times Mexico's GDP, and 94.6% of the payments made by end users were for 1,500 UDIS or less. Non-bank institutions, which have joined in growing numbers, handled 19.8% of all operations.
Mexico does not use IBANs. The CLABE does that job for domestic payments, and IBAN explained shows how the international format differs.
How is an 18-digit CLABE built?
A CLABE, or Clave Bancaria Estandarizada, packs four pieces of information into 18 digits: the bank, the plaza, the account number and a check digit.
| Positions | Length | What it identifies |
|---|---|---|
| 1 to 3 | 3 digits | The bank, using codes assigned through the Asociación de Bancos de México |
| 4 to 6 | 3 digits | The plaza, meaning the city or region where the account is held |
| 7 to 17 | 11 digits | The account number the bank uses internally |
| 18 | 1 digit | The check digit, calculated from the first 17 |
According to the banking association, each CLABE is unique to one account, so a transfer quoting it can land only in that account. Because the first three digits name the bank, a glance also tells you whether a CLABE belongs to the institution the recipient mentioned; if it does not, stop and ask before paying.
How do you check a CLABE's control digit?
Weight the first 17 digits by 3, 7 and 1 in turn, add the last digit of each product, then subtract the total's last digit from 10. If the subtraction gives 10, the check digit is 0. The banking association publishes the method, and banking apps can use it to reject a mistyped number before a payment goes out.
Worked example: Working out the check digit of a made-up CLABE
The first 17 digits below are invented: bank code 000, plaza 180 and account 01234567890. Do not send money to the result.
| Digit position | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Digit | 0 | 0 | 0 | 1 | 8 | 0 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 |
| Weight | 3 | 7 | 1 | 3 | 7 | 1 | 3 | 7 | 1 | 3 | 7 | 1 | 3 | 7 | 1 | 3 | 7 |
| Product | 0 | 0 | 0 | 3 | 56 | 0 | 0 | 7 | 2 | 9 | 28 | 5 | 18 | 49 | 8 | 27 | 0 |
| Last digit | 0 | 0 | 0 | 3 | 6 | 0 | 0 | 7 | 2 | 9 | 8 | 5 | 8 | 9 | 8 | 7 | 0 |
- The last digits add up to 72, whose last digit is 2.
- 10 − 2 = 8, so the check digit is 8 and the full number is 000180012345678908.
- The banking association's own sample, 002115016003269411, works the same way: its last digits add up to 59, and 10 − 9 = 1, matching its final digit.
Testing every possible slip shows what the check digit can and cannot do. It catches any single wrong digit, and it catches a swap of two neighboring digits unless they differ by exactly 5, such as 2 and 7. What it can never catch is a correct CLABE that belongs to the wrong person, which is the weakness behind the frauds described at the end of this guide.
How fast is a SPEI transfer, day or night?
Speed depends on the amount and the hour: banks must credit transfers of up to 1,500 UDIS within 5 seconds, at any hour of any day. UDIS, or unidades de inversión, are an inflation-linked unit that Banxico publishes daily. The SPEI rules convert them at their value on January 1, which for 2026 is MXN 8.666288, putting the 1,500-UDIS line at MXN 12,999.43 and the 6,000-UDIS line at MXN 51,997.73.
| Transfer | When the receiving bank gets it | Deadline to credit the account |
|---|---|---|
| Up to 1,500 UDIS, about MXN 13,000 | Any time, every day | 5 seconds |
| Above 1,500 UDIS | Business days, from 6 a.m. until the evening close | 30 seconds |
| Above 1,500 UDIS | Nights, weekends and holidays | 6:00:05 a.m. on the next banking day |
| 6,000 UDIS or more, about MXN 52,000 | Any time | Longer, if Banxico has authorized the bank to run extra checks |
| CoDi payment | Any time, every day | 4 seconds |
The receiving bank must also tell the recipient, free of charge, within 5 seconds of crediting the money, and the sending bank must ask for a second authentication factor on transfers above 1,500 UDIS. Institutions with fewer than 3,000 accounts are exempt from the round-the-clock rule and credit small payments during business-day hours.
Many institutions go beyond the minimum. Of the 63 institutions offering SPEI transfers to their customers in Banxico's 2025 survey, 71.9% let them send up to 1,500 UDIS around the clock and 59.4% did the same for larger amounts.
Worked example: $750 sent to a CLABE on a Tuesday night
Assume 1 USD = 18.80 MXN, an illustrative rate. A provider converts $750 into MXN 14,100 and pays it by SPEI at 11 p.m. on a Tuesday.
- MXN 14,100 is above the 2026 low-value line of MXN 12,999.43, so the 5-second rule does not apply.
- If the recipient's bank does not credit large transfers overnight, it can wait until 6:00:05 a.m. on Wednesday.
- A $650 transfer, worth MXN 12,220 at the same rate, falls under the line and must be credited within 5 seconds, whatever the hour.
What is a CEP and how do you get one?
A CEP, or Comprobante Electrónico de Pago, is Banxico's official receipt showing that a SPEI transfer was credited to the destination account. It is built from the confirmation the receiving bank sends back through SPEI, so it proves that the money arrived, not merely that it left. Banxico has issued CEPs since February 24, 2012, as PDF and XML files, through its CEP page.
Copy the details from the sender's receipt
You need the payment date, the tracking key (clave de rastreo, up to 30 letters and numbers) or the numeric reference of up to 7 digits, the sending and receiving institutions, the destination account and the exact amount.
Look the payment up on the CEP page
Enter the details on Banxico's CEP page. It shows the status of the payment and, once it has been credited, offers the receipt.
Download and keep the PDF and XML
The XML version can be checked with Banxico's CEP validator, which accepts up to 100 files at a time.
Recheck before assuming the worst
If nothing is found, compare every field with the receipt, especially the date and the amount to the centavo, then ask the sending bank. Banxico also answers questions on 800 226 9426, option 2.
A CEP is the right test for any payment someone claims to have made to you. Screenshots and forwarded emails can be edited, while a CEP comes from Banxico's own records.
What are CoDi and Dimo?
CoDi and Dimo are Banxico services that run on SPEI: CoDi handles payment requests by QR code or NFC, and Dimo sends money to a phone number.
| Feature | CoDi (Cobro Digital) | Dimo |
|---|---|---|
| Available since | September 2019 | February 23, 2023 |
| How it works | The payee sends a payment request as a QR code or NFC message, and the payer accepts it in a banking app | The recipient links a mobile number to one account, and senders type the number instead of a CLABE |
| Participants at the end of 2025 | 32 | 25, with 15 more joining |
| Use in 2025 | 4.4 million operations | 16.4 million registered users and 3.1 million transfers between institutions |
Banxico says CoDi payments carry no fees, yet 4.4 million operations a year is tiny next to SPEI's 7.3 billion. Dimo is growing faster. The recipient must have linked their number first, and each number points to only one account at a time: the last one its owner authorized.
Banxico is also standardizing the transfer screens themselves. Circular 9/2026, in force since June 18, 2026, requires banking apps to offer the same ways to start a transfer, including a CLABE, a debit card number, a Dimo phone number or a QR code, and to show at least the amount, the recipient's name, which may be partly masked, the account and the institution before you confirm. Banks have until December 14, 2026 to comply.
How do dollars sent from the US reach a CLABE?
SPEI moves only pesos, so dollars from the US are converted first and then paid into the recipient's account by a Mexican institution. With a transfer service, the provider or its partner in Mexico receives the funds, converts them and sends a SPEI payment to the CLABE or debit card number you supply. Banxico defined special SPEI messages for remittances in 2024, in use since March of that year, so the receiving bank can see that the money is a remittance from abroad.
A wire from a US bank instead travels through correspondent banks to the recipient's Mexican bank, which converts it; SPEI is involved only if the money then moves on to another bank. A third route is closing. Directo a México, the service the Federal Reserve and Banxico ran through FedGlobal ACH, converted at Banxico's FIX rate less 0.21% and credited accounts the next business day, but it takes its last payments on November 20, 2026 and handles returns only until December 11, 2026.
Details to get from a recipient in Mexico
- Their full name exactly as the bank holds it
- The 18-digit CLABE, read back by the recipient rather than copied from a forwarded message
- The bank's name, which should match the CLABE's first three digits
- A phone number to confirm the money arrived and, if needed, to share the tracking key
How you pay on the US side matters too. The federal remittance tax is 1% of the amount sent, on transfers paid with cash, a money order, a cashier's check or a similar physical instrument, so paying by bank transfer or with a US-issued card avoids it. For providers, costs and timing on this route, see sending money from the US to Mexico.
How does a SPEI deposit compare with cash pickup or a debit card payout?
A CLABE deposit leaves a trail Banxico can confirm, cash pickup needs no bank account, and a card payout needs only a debit card number.
| Feature | Deposit to a CLABE | Cash pickup | Payout to a debit card |
|---|---|---|---|
| What the recipient needs | A bank account and its CLABE | Official ID and the transfer reference | A Mexican debit card number |
| Proof of arrival | Banxico's CEP | The agent's receipt | A CEP if paid by SPEI, otherwise the account statement |
| How the money can be used | Spent, saved or sent on from the account | In cash, once collected | Like a deposit, from the card's account |
| Main risk | A valid CLABE that belongs to someone else | Carrying cash home and agent opening hours | A mistyped or replaced card number |
Mexico is split almost evenly between the two main ways of collecting. On Banxico's revised figures, Mexico received USD 62,472 million in remittances in 2025, and of the money sent electronically, 49.6% was collected in cash and 50.4% went into accounts.
For a live benchmark, the next table converts $200, $500 and $1,000 into pesos at the current mid-market rate and then applies markups of 1% and 3%; flat fees come on top.
| You send | At the mid-market rate | With a 1% markup | With a 3% markup |
|---|---|---|---|
| $200 | MX$3,761 | MX$3,723 | MX$3,648 |
| $500 | MX$9,403 | MX$9,309 | MX$9,121 |
| $1,000 | MX$18,805 | MX$18,617 | MX$18,241 |
The money transfer cost calculator finds the markup hidden in any quote. Its fields are labelled in pounds and rupees, but entering dollar and peso figures, including the mid-market rate, gives the right percentage.
Which SPEI frauds should you watch for?
The frauds that target SPEI users exploit two facts: payments are instant and final, and the recipient's name plays no part in where the money goes.
- Fake deposit receipts. In what Mexico City's cyber police call the depósito fantasma, a buyer sends an edited or app-generated receipt and presses the seller to hand over goods, but the money never arrives. Check the balance in your own banking app or download the CEP before releasing anything.
- A real company's name with someone else's CLABE. CONDUSEF, the financial consumer agency, warns that SPEI identifies the payee only by CLABE, account number or card number, so typing a well-known company's name into the order does not stop the money reaching a stranger. Confirm the CLABE with the company directly.
- Altered details in messages. A CLABE sent by chat or email can be changed along the way, and a different but valid number passes the check digit. Read it back with the recipient by phone before the first payment.
- Account takeovers. Anyone who obtains a banking password, token or one-time code can empty an account through SPEI in seconds. Never share those codes, even with a caller who claims to be from the bank.
If a payment does go to a fraudster, call your bank at once with the tracking key, because speed gives the banks the best chance to stop the money moving on. For reporting from the US, see money transfer scams. SPEI is one of several national systems covered in this series: Pix in Brazil, SEPA in Europe and mobile money handle the same final step elsewhere.