Mexican payment references: concepto, referencia, convenio

The two identification fields on a SPEI transfer

SPEI is the real-time interbank transfer system operated by Banxico, Mexico's central bank. When a customer sets up a transfer to your CLABE (the 18-digit account number), their banking app asks for:

Field	Spanish	Format	Typical content
Numeric reference	Referencia numérica	Digits only, up to 7	A customer or invoice code
Concept	Concepto de pago	Short free text	"FACT 1043", a name, or "PAGO"

Both fields are optional in practice. Many apps pre-fill them with a default, and customers accept it. How these fields end up on your statement depends on your bank, as described in SPEI explained.

Designing a reference customers will actually type

A good reference scheme is short, numeric, unique per customer and stable over time. Illustrative design for a subsidiary with 400 business customers:

Element	Example	Why
Customer number	0412	Stable, survives invoice changes
Check digit	7	Catches a mistyped digit
Full reference	04127	Fits in the 7-digit field

Print it on every invoice, in the payment instructions email and on the customer's account statement, with the sentence "Type this number in the Referencia field." A reference per customer, rather than per invoice, survives when one transfer pays several invoices.

Bank collection agreements and the CIE model

Large collectors often use a bank's referenced-collection service. The bank gives you an agreement number (convenio), and each payer quotes the convenio plus a reference that follows an algorithm you agree with the bank. The bank can reject payments whose reference fails validation, so what arrives is already identified.

BBVA México's version is widely known as CIE (Concentración Inmediata Empresarial), and many Mexican customers recognise the term. Other banks offer equivalents under their own names. Agreements typically support branch cash, transfers and sometimes card payments, and the bank delivers a daily file of identified payments.

The Spanish guide to bank collection agreements covers setup in more depth.

Cash payments at OXXO and other stores

Many Mexican consumers and small businesses pay in cash at convenience stores, OXXO being the largest chain. To accept this, you work through a bank agreement or a payment provider that issues a reference or barcode per payment. The customer pays the cashier, and the money arrives later as a settlement, often grouped with other payments. You then need the provider's report to split the settlement into individual customers.

At a high level, cash channels trade convenience for the customer against settlement delays and an extra reconciliation file for you.

What happens when there is no reference at all

Without a reference you are matching on amount, date and payer name. That works when amounts are distinctive, and fails when many customers owe the same amount. The fallout is covered in unidentified deposits in Mexico.

Making references survive a change of bank

Groups that switch banks, or add a second bank, often lose their reference discipline in the move. Keep the customer reference independent of the bank: the same number should work with any account. When you change account details, send customers one notice with the new CLABE and the unchanged reference, and keep the old account open long enough to catch late payers.

Choosing a scheme for your Mexican entity

Situation	Suggested approach
Few business customers, distinct amounts	Customer reference in the numeric field
Many customers, similar amounts	Bank collection agreement or dedicated CLABEs
Consumers paying in cash	Store-network references through a provider
Mixed	Agreement for volume, manual reference for the rest

Reading references when they are inconsistent

Even with a good scheme, some customers will type the reference in the concept, add spaces or swap digits. Meses (meses.ai) can help with that part. Meses reads your bank statement PDF and your records in Google Sheets, Excel or CSV; AI proposes which customer and period each deposit belongs to, your team reviews the proposals, and Meses writes approved payments back to your sheet, with undo. Meses processes your statements securely: the PDF is not sent to an AI provider, and personal data is protected before any AI analysis.