SPEI (Mexico's interbank transfer system, run by Banxico) is a real-time system that moves pesos between accounts at different Mexican institutions, around the clock. The payer needs the recipient's CLABE (the 18-digit bank account number), a debit card number or a phone number. A payment should take no more than 30 seconds, Banxico says.
Speed is not what catches teams out. A CLABE one digit off, and a supplier who has not been paid while the money sits in a stranger's account, is the case SPEI does not undo.
What is SPEI and who runs it?
SPEI is infrastructure owned and operated by Banco de México, the central bank, which administers it as a real-time settlement system. It began operating on August 13, 2004, runs on a 24/7 schedule and replaced an older system called SPEUA. It carries pesos between institutions within Mexico.
Item | What the source says | Source |
Operator and administrator | Banco de México | Banxico SPEI page |
Type | Real-time settlement system | Banxico SPEI page |
Start of operation | August 13, 2004 | Banxico SPEI page |
Payment time | Should not take more than 30 seconds | Banxico user information |
Who connects | Participants, under Circular 14/2017 | Banxico SPEI page |
SPEI at a glance, from Banxico's SPEI pages, checked November 6, 2026.
Participants are federally regulated financial entities (supervised by Banxico, the CNBV (the banking and securities regulator) or the insurance and pension commissions), federal public bodies, Banxico as a trustee and foreign-exchange settlement systems that include the peso. All have to meet Circular 14/2017, the rules the SPEI page names. A company that is not a participant reaches SPEI through one that is.
On Lumx, the MXN account is issued by a banking partner, and that partner executes the rail. Whether stablecoins are allowed inside a Mexican institution is a separate question, in stablecoin regulation in Mexico.
How does a SPEI transfer move from payer to recipient?
The payer never talks to Banxico. The central bank sits in the middle of the chain.
Step | Who acts | What happens |
1 | Payer | Enters, checks and confirms the transfer in the bank's app or website |
2 | Sending institution | Receives the order and validates it automatically |
3 | Banxico | Receives, validates and forwards the order to the receiving institution |
4 | Receiving institution | Checks the order, credits the beneficiary account and confirms the credit to SPEI |
5 | Recipient | Sees the funds and can look up the CEP, the electronic payment receipt |
A SPEI transfer in five steps. Source: Banxico, SPEI page, checked November 6, 2026.
SPEI payments always run between accounts at different banks.
For a payout, Lumx runs this chain from a stablecoin balance. You send one off-ramp request, Lumx converts the stablecoin to MXN, and the pesos go out over SPEI to the registered account. The payout passes through a stablecoin transfer, a conversion and a fiat transfer before it succeeds, with a webhook at each step. The off-ramp explainer covers the steps.
What a payer needs to send a SPEI payment
Three identifiers work: the CLABE (18 digits), the debit card number (16 digits) or the cell phone number (10 digits) tied to the account. The payer also gives a reference number (up to seven digits) and a description (up to 40 characters), and the bank returns a search code that identifies the payment later.
Internet banking asks the payer to register the receiving account first, with a waiting period before use. Mobile banking only asks for registration when the payment is above 250 UDIS (Unidades de Inversión, a Mexican inflation-indexed unit whose peso value changes daily, so a fixed conversion would go stale). Some banks also ask the payer to set a payment limit when registering an account, which is why the per-bank cap sits in the table below.
SPEI routes on the number. The user information describes the payer supplying the identifier and getting a receipt afterwards, and it does not describe a name check before release. The holder's name is something you verify before you save the account, as we lay out in Verification of Payee by rail.
On Lumx, the destination for a SPEI payout takes the CLABE, which must be exactly 18 digits or the request is rejected. It also takes a holder type, the name, the tax ID (the RFC for Mexico) and a relationship such as supplier, employee or self. The destination starts under verification, and the payout waits until it is approved.
How fast SPEI is, and whether it runs on weekends
SPEI payments and transfers should not take more than 30 seconds, and bank channels are available 24 hours a day, every day. The CEP is issued once the receiving bank confirms the deposit, which can take up to 30 minutes, and it can be consulted for payments from the last 45 working days.
On Banxico's schedule the rail has no cut-off hour and no weekend gap, yet its own status list still includes a cancellation at the close of operations (see the status table below): a deposit not authorized by then is cancelled. How SPEI sits next to the other Latin American push rails is in Pix, SPEI, PSE and Bre-B compared.
On Lumx, SPEI has no cut-off and runs 24/7/365, and the Coverage page lists its settlement as instant. The cut-off table points to Banxico's calendar of días inhábiles bancarios for holidays. If a bank holiday ever stops SPEI settlement, the payout waits at the fiat transfer step and settles when the rail is back. These are targets, not guarantees: a review hold or a hold at the recipient's bank adds time, so build the screen around webhook events, not the clock.
SPEI next to Pix and Bre-B
Rail | Timing | Weekends | After the deposit |
SPEI (Mexico) | Not more than 30 seconds after approval | Bank channels 24 hours a day, every day | Cannot be cancelled; the receiving bank can return it |
Pix (Brazil) | Real time | Yes, every day | A return can be started within 90 days; a special mechanism covers suspected fraud and operational failure |
Bre-B (Colombia) | Seconds | Yes, holidays included | No return procedure in the sources read |
Three Latin American push rails side by side. Source: the operator pages summarized in the rails comparison, checked October 29, 2026.
They look alike on speed and differ after a mistake. On Lumx, all three pay out from the same stablecoin balance, and Lumx deducts no fee from the amount the recipient receives on any of them.
What does SPEI cost, and what are the limits?
Item | Who sets it | What the sources say |
Participant fee | Banxico | Fixed fee plus a fee per operation, charged to participants |
Fee to the payer | The payer's bank | Banxico says the service generally has a cost, monthly or per service |
Per-transaction cap | Each bank | No figure on the Banxico pages read (checked November 6, 2026); some banks ask the payer to set a limit when registering an account |
Account pre-registration | Each bank | Required in internet banking, above 250 UDIS in mobile banking |
Fee to the recipient | The recipient's bank | Not described on the Banxico pages read |
Who charges what on a SPEI payment, from Banxico's SPEI pages, checked November 6, 2026.
The practical limit is the one your own provider sets. On Lumx, limits attach to the customer and are measured in the USD equivalent of the transaction. The ceiling depends on the verification level: standard KYB (know your business, the verification of a company and its owners) for companies, standard KYC (know your customer, the verification of an individual) for people, and Enhanced verification raises both. Each transaction type counts against its own limit, and the Transaction limits page in the docs holds the current figures.
Lumx deducts nothing from the pesos that arrive on a SPEI payout; only the recipient's bank can. The final target amount in a quote is what the recipient receives, net of Lumx fees and any partner fee you attach.
What happens when a SPEI payment fails or has to come back?
A supplier calls to say a payment never arrived, and the CLABE on your side was one digit off. Two tools show where it went: the CEP, issued by Banxico as proof that the payment was made, and MI-SPEI, an information service that looks a payment up by its search code or reference number. If the CEP cannot be obtained, the payment may not have gone through and may have been returned, and MI-SPEI is the next stop.
Status | What it means |
Being processed | SPEI received the request, and the money has not yet been deposited |
Liquidated | SPEI processed the payment, and the receiving bank can credit the account |
Cancelled | The payer's bank cancelled it before the money moved |
Rejected | SPEI refused it because of errors or inconsistent data |
Undergoing return | The receiving bank returned it, and the amount is on its way back |
Returned | The receiving bank returned it, and the amount should be back with the payer |
Cancelled at the close | The deposit was not authorized before SPEI closed operations |
MI-SPEI payment statuses. Source: Banxico, user information for SPEI users, checked November 6, 2026.
The line that matters most is in the Cancelled row. A payment can be cancelled before the money is transferred, but once the money is deposited, the transaction cannot be cancelled. A wrong CLABE that belongs to a real account is therefore not an error SPEI fixes. Getting the money back depends on the receiving bank and the holder; ask your own bank and counsel.
On Lumx, a payout that fails surfaces as a failure event, and a payout held for review waits in the state it reached until the review closes. Most causes sit before any money moves, and they come back as an error: an unapproved destination, a wallet short of the amount or a limit passed. On collections, a third-party payer is allowed, but an unusual one can trigger an RFI (request for information, a compliance hold that asks for a document before a transaction clears) and, as a consequence, a return of the deposit.
Check the account before the first payment
I would take the CLABE from a signed invoice or a bank letter, never from an email that says the details changed, and I would pay a small test amount before the first large payout to a new Mexican supplier. SPEI cannot be cancelled once the money is deposited, so the only cheap place to catch a wrong account is before the first transfer. The test payment removes the one failure SPEI cannot undo.
Receiving SPEI payments as a company outside Mexico
A company outside Mexico can hold a named MXN account without a local entity in Mexico, Lumx's position. A named virtual account is a local account number issued in the customer's own name, so the CLABE you give a payer identifies your customer, not a pool. Collections arrive over SPEI, and each deposit can convert to a stablecoin automatically.
Lumx is stablecoin payments infrastructure for businesses that move money between Latin America and the rest of the world: one API to collect, hold, convert, and pay out in BRL, MXN, COP, USD, EUR, and GBP or in USDC and USDT, over local rails such as PIX, SPEI, PSE, Bre-B, ACH, FEDWIRE, SEPA, and Faster Payments, with SWIFT and on-behalf-of payments and collections (POBO and COBO) in USD, EUR, and GBP, plus named virtual accounts, custodial wallets, and KYB/KYC built in.
You request MXN in the accounts array when you create the customer. The account becomes active right after the customer is approved, and a webhook tells you the moment it can receive funds. An autoconversion rule carries a static CLABE and a memo reference, reused for every deposit, and the memo is what matches a deposit to the rule. The stablecoin reaches the customer's wallet within about 5 minutes. Anyone with a Mexican bank account can pay into the CLABE over SPEI, and Lumx allows a third-party payer on collections. Rates and routes for the pair are on the MXN to USDC page.
On the way out, the recipient's bank statement shows your customer as the sender of the SPEI payment, because the account is named. You quote the conversion, floating or locked for up to five minutes, and the off-ramp pays the CLABE. USDC to MXN shows the pair, what USDC is covers the asset, and send USDC to Mexico walks through the payout step by step. Product details are on named virtual accounts, and every rail and pair on the payment coverage page.
When SPEI is the wrong rail
SPEI pays pesos inside Mexico, so it is wrong for a recipient who banks abroad or expects dollars. A Mexican company paying a US supplier needs a dollar rail, covered in paying US suppliers. With Lumx, a USD account collects and pays out over ACH, Fedwire and SWIFT.
It is also the wrong rail when you hold none of the three identifiers for the recipient, and when you need a transfer you can pull back.
Methodology and sources
SPEI facts come from two Banxico pages: the SPEI information page (operator, type, start date, 24/7 schedule, participants, Circular 14/2017, fees to participants) and the user information page (identifiers, the 30-second figure, the 250 UDIS rule, CEP and MI-SPEI statuses, cancellation after deposit). The CEP page shows how the receipt is looked up. All three were read on November 6, 2026. Circulars 13/2017 and 14/2017 appear only as the SPEI page names them, and that page sends readers to the Regulación y supervisión section of banxico.org.mx for the texts, so this post gives no issue date for either and makes no claim about their content.
Two statements are negative and were checked: the Banxico pages read give no per-transaction ceiling and no return procedure for a wrong but valid account. If Banxico publishes either, this post is out of date.
Lumx facts come from our public documentation, read November 6, 2026: Convert USDT to MXN and pay out over SPEI, Accounts, Destinations, Transaction limits, Autoconversion rules, Sender of record and Coverage.
Verified on November 6, 2026. Operational context, not legal, tax, or investment advice.
Cover photo: Jakub Żerdzicki on Unsplash.
What is SPEI?
SPEI is Mexico's interbank electronic payment system, developed and operated by Banco de México. It moves pesos between accounts at different institutions in Mexico, and Banxico says a payment should take no more than 30 seconds. Lumx pays out and collects over SPEI through MXN accounts that a banking partner issues in the customer's name.
How long does a SPEI transfer take?
Banxico says SPEI payments should not take more than 30 seconds, and bank channels run every hour of every day. The receipt can take up to 30 minutes to be issued. On Lumx, SPEI has no cut-off and settles instantly, 24/7/365, and the payout moves from the stablecoin transfer to the fiat transfer with a webhook at each step.
Can a SPEI payment be cancelled or reversed?
Not once the money is deposited. A payment can be cancelled before the transfer, and after the deposit the transaction cannot be cancelled. The receiving bank can still return it, which MI-SPEI shows as a return status. On Lumx, a payout is only sent to an approved destination: it starts under verification and the payout waits for approval, so a destination that fails verification never receives money.
What is a CLABE?
A CLABE is the 18-digit standardized bank code that identifies a Mexican bank account, and it is the identifier a SPEI payer most often uses. Banxico also lists a 16-digit debit card or a 10-digit cell phone number. On Lumx, a SPEI destination takes the CLABE with a holder type, a name, the RFC and a relationship, and a CLABE that is not 18 digits is rejected.
Can a company outside Mexico use SPEI?
Yes, through a provider that holds an account in Mexico. On Lumx, a company with no Mexican entity can hold a named MXN account, collect pesos over SPEI into a stablecoin wallet and pay Mexican recipients from it.
