ACH to SPEI: how companies move money from the US to Mexico

Companies that move money from the United States to Mexico usually balance three things: cost, speed, and operational certainty. ACH and SPEI are popular because they can be efficient local rails: ACH is a common way to move dollars inside the United States, and SPEI is the core local rail for peso payments in Mexico.

The hard part is not understanding the acronyms. The hard part is designing the flow between them: who receives USD, when it is converted, who pays MXN, what proof exists, and what happens when a payment misses a cutoff.

What is ACH?

ACH stands for Automated Clearing House. It is a US domestic payment network commonly used for payroll, vendor payments, collections, and account-to-account transfers.

For companies, ACH is useful because it is familiar and often lower-cost than a wire. The tradeoff is time. Depending on the bank, payment type, and processing window, ACH can take one or more business days. Same-day ACH exists, but it is not the default for every flow or every bank.

That is why many companies like ACH when the payment is predictable. If you can plan ahead, ACH can be a good way to collect or move USD without paying wire-level fees every time.

What is SPEI?

SPEI is Mexico’s electronic payment system for peso transfers. For many domestic MXN payments, SPEI is fast, widely used, and available beyond traditional branch hours.

For Mexican suppliers, carriers, payroll providers, and local vendors, SPEI is often the practical way they expect to receive pesos. It is not exotic. It is the normal local rail.

The challenge appears when the company has dollars on the US side and obligations in pesos on the Mexico side. SPEI can solve the last mile in Mexico, but the business still needs a clean way to get from USD to MXN.

Why companies use ACH and SPEI together

Many cross-border operators prefer a slower but cheaper path when the payment is not urgent:

1. Receive or collect USD in the United States.
2. Move or hold those dollars through a US account.
3. Convert USD to MXN when the rate and timing make sense.
4. Pay the Mexican beneficiary by SPEI.
5. Keep the receipt and reconcile the flow.

This can be a strong approach when the company has planning discipline. If supplier payments are scheduled, if payroll dates are known, and if cash flow is predictable, the business can use lower-cost rails and avoid emergency fees.

In other words: time can be a tool. Companies often spend time to avoid fees because it is rational.

Where SWIFT fits

SWIFT is the traditional network used by banks for many international transfers. It is broad and well-established, but it can be slower, less predictable, and harder to reconcile for day-to-day operating payments.

A SWIFT payment can involve intermediary banks, additional fees, compliance checks, and less transparent status information. For a large occasional international wire, that may be acceptable. For recurring supplier operations, it can create friction.

The question is not whether SWIFT is good or bad. The question is whether it is the right rail for this specific payment.

ACH, wire, SWIFT, and SPEI compared

Rail	Where it is strongest	Typical tradeoff
ACH	Lower-cost USD movements inside the United States	Not always instant; depends on processing windows
US wire	Faster high-value USD movement	Higher cost and bank cutoff dependency
SWIFT	Traditional international bank-to-bank transfers	Can be slower, more opaque, and intermediary-heavy
SPEI	Local MXN payments in Mexico	Needs a prior USD-to-MXN and funding flow if money starts in the US

The best flow often combines rails instead of forcing every payment through one method.

The real operating question

A finance team should not only ask, “Can we send money from the US to Mexico?”

It should ask:

• Can we receive or hold USD locally?
• Can we convert to MXN when needed?
• Can we pay the supplier through the right local rail?
• Can we prove the payment happened?
• Can we reconcile it without chasing screenshots?
• Can we do it when the bank portal or FX desk is closed?

That is the difference between a transfer and an operating flow.

When ACH to SPEI works well

ACH-to-SPEI style flows work best when:

• the payment is planned;
• the supplier can wait for the normal settlement window;
• the amount is recurring or predictable;
• the company wants to reduce avoidable fees;
• the team has a clean process for FX, proof, and reconciliation.

When it breaks down

The same flow becomes painful when:

• a supplier needs payment today;
• the US collection arrives late;
• the bank cutoff has already passed;
• the team needs MXN now but funds are still sitting in USD;
• proof of payment matters for releasing a shipment or service;
• no one knows whether the payment is created, sent, received, or stuck.

That is when “cheap” can become expensive operationally.

How Coba thinks about it

At Coba, we like rails that are useful. ACH is useful. SPEI is useful. Wires are useful. SWIFT can be useful too.

The problem is when a business has to stitch them together manually every time. Coba Banking is built around the workflow between the rails: receiving or holding USD where applicable, converting USD/MXN, paying locally, giving teams clearer status, and routing prospects into the right next step.

If you are evaluating a US-to-Mexico payment flow, start with the business question: do you need the cheapest path, the fastest path, or the clearest operating process?

Often, the answer is not one rail. It is the right flow.

Explore USD/MXN business payments or request current pricing.