An EU-based SaaS vendor selling subscriptions in Mexico had grown beyond the point where sporadic USD/EUR wires and card acquiring covered its needs. Customers—mid-market distributors and professional services firms—wanted to pay invoices in MXN from domestic accounts, avoid cross-border fees, and receive refunds quickly if a billing dispute occurred. Finance and ops wanted predictable reconciliation, better FX outcomes, and fewer support tickets about missing payments. This is the story of how the company shifted from SWIFT wires to local MXN collections over SPEI, and what changed operationally, financially, and from a risk standpoint.
The starting point: SWIFT as the default
Before the change, Mexican clients paid quarterly or annual invoices in USD or EUR via SWIFT to the company’s EU bank. That baseline created friction:
- Uncertain settlement times: transfers arrived in two to five business days depending on intermediaries, public holidays, and cut-offs.
- Opaque and cumulative fees: originator and intermediary bank charges eroded invoice proceeds, forcing manual short-payment write-offs or back-and-forths with customers.
- FX spread pain: customers disliked converting MXN to USD/EUR; rates varied wildly and were hard to audit, especially for procurement departments.
- Refund latency: when credits were due, the finance team had to initiate international wires back to MXN beneficiaries, adding more fees and days of waiting.
- Reconciliation overhead: generic SWIFT references and broken remittance data meant frequent manual matching and delayed revenue recognition.
The go-to workaround—card acquiring—helped for smaller tickets but introduced interchange and cross-border assessment fees, higher fraud ops, and limited acceptance among B2B buyers accustomed to bank transfers.
What changed with SPEI
SPEI is Mexico’s real-time interbank system used for domestic MXN transfers. By enabling local MXN collection via a licensed partner connected to SPEI (through a settlement bank), the SaaS company could give each Mexican payer a virtual CLABE (MX 18-digit account number) or payment link for one-off invoices. That single decision flipped the operating model:
- Domestic, instant settlement: funds arrived in minutes during banking hours, typically same-day even near cut-off windows.
- Predictable cost base: local transfer fees are negligible compared to cross-border wire chains; proceeds hit close to face value.
- Cleaner reconciliation: structured references plus payer-bound virtual accounts turned matching into an automated rule rather than a manual task.
- Refunds via SPEI: credits back to customers became domestic instant pushes, bringing down support tickets and DSO for negative balances.
- FX on the company’s terms: the firm could choose when and how to convert MXN to EUR—daily sweeps, balance-based triggers, or market-linked thresholds—rather than forcing customers to handle FX.
Operating model and architecture
The target architecture layered new capabilities without rewriting core billing:
- Billing system continues to create invoices in MXN with a unique reference and due date.
- Payments orchestration requests a virtual CLABE per debtor or per invoice through the local provider.
- Customer pays via their domestic bank app or portal over SPEI to the provided CLABE.
- Settlement ledger records the incoming credit; a webhook posts to the finance system to mark the invoice as paid.
- Refunds or adjustments are initiated as domestic outbound SPEI to the original payer’s account.
- FX and repatriation: balances are converted in batches to EUR and sent to the EU treasury account; EUR proceeds are booked against the same invoice set.
Security and compliance controls sit at the provider layer (onboarding, KYC/KYB, AML screening, sanctions, transaction monitoring). The SaaS company maintains governance: approved counterparty lists, dual control on payouts, and automated alerts for unusual settlement patterns.
Compliance and tax contours to watch
Mexico is a mature e-invoicing jurisdiction. While the SaaS company did not establish a full local entity at the outset, it had to align with practical realities that affect collections and acceptability for enterprise clients:
- Invoice data standards: counterparties often expect invoices with CFDI-compatible fields and correct tax treatment (e.g., VAT/IVA relevance depending on service, place of supply, and customer type).
- RFC identifiers: enterprise buyers typically require their RFC on documents and remittances so they can reconcile payments internally.
- Remittance structure: SPEI messages allow references, but finance teams benefited from attaching payment references that mirror invoice numbers and customer IDs to avoid downstream mismatches.
- AML/transaction monitoring: thresholds, velocity checks, and alerts for unusual patterns (e.g., many micro-credits from unrelated accounts) are handled by the provider, but the SaaS company still defined escalation paths and evidence retention for audits.
These are operational guardrails rather than legal opinions; the key takeaway is to plan the document and data layer early so collections are “enterprise-grade” on day one.
Rollout plan and what actually happened
The company executed the migration in three waves:
Wave 1 — Pilot on high-friction accounts.
Ten customers with recurring wire issues were moved first. They received new MXN invoices with a virtual CLABE and a short explainer: “Domestic SPEI transfer, reference INV-XXXX, no cross-border fees.” Finance tracked KPIs—time-to-clear, short-payment rate, and support tickets.
Wave 2 — New sales and renewals.
All renewals from month two onward and all new sales were quoted in MXN by default with SPEI as the primary method. Card remained as a fallback for small monthly plans.
Wave 3 — Full portfolio migration.
Legacy annual contracts were shifted at their next billing cycle. FX and treasury policies were finalized: daily MXN→EUR conversion if the balance exceeded a set threshold, otherwise weekly.
Results and measurable impact
After three months, the data told a consistent story:
- Settlement time: median time from payment initiation to invoice closed dropped from T+3 business days to under one hour.
- Net proceeds per invoice: fees and short-payments decreased; the company realized an effective improvement of 120–180 bps on collections versus the SWIFT baseline.
- Refund experience: average refund turnaround moved from 4–7 days to same-day, reducing escalation tickets.
- Reconciliation automation: automated matching covered >95% of payments using virtual CLABE and references; manual cases were usually typos in external PO numbers.
- Cash forecasting: real-time settlement enabled tighter working-capital forecasts; the treasury team adjusted sweeps to EUR to match payroll and vendor cycles.
These are indicative figures from this program; different mixes of invoice sizes and payer behavior will produce different deltas, but the directional gains held across cohorts.
Risk, fraud, and operational controls
Domestic instant rails increase speed; they don’t eliminate risk. The team addressed three classes of exposure:
- Misapplied funds: solved through payer-specific virtual accounts, strict reference formats, and alerts for unexpected senders.
- Refund abuse: outbound SPEI refunds are restricted to the original source account unless finance approves an exception with additional verification.
- Account takeover attempts: role-based access control, SSO for finance tools, and dual approval on any payout templates or whitelist changes.
Provider-level transaction monitoring added velocity and anomaly checks. A monthly joint review (provider + finance) looked at alert stats, false positives, and threshold tuning.
FX strategy and repatriation
SPEI collections leave the firm with MXN balances. The team formalized a few practices:
- Hedging light: given short balance duration, they didn’t implement forwards on day one; instead, they used time-and-threshold-based sweeps to EUR.
- Price discovery: the treasury portal displayed live executable quotes across counterparties. Reporting captured the achieved rate versus a daily benchmark to quantify realized spread.
- Invoicing currency policy: enterprise contracts stayed in MXN to align with buyer expectations; EUR-denominated contracts were offered only when the buyer insisted on EUR budgeting.
Customer communications
Adoption hinged on simple, unambiguous instructions:
- Invoices included the virtual CLABE, beneficiary name, and reference formatting.
- A one-page FAQ listed common bank app flows (“SPEI transfer → capture reference exactly as shown”).
- For AP teams, the company provided a standing vendor profile with the CLABE and tax fields to save in their systems.
- Refund policy explained that credits would return via SPEI to the original account, typically same-day after approval.
Clear communication reduced friction and normalized SPEI as the default within two billing cycles.
What the finance stack looked like afterward
The finance and ops tools evolved from inbox-driven reconciliation to event-driven accounting:
- Webhooks from the provider posted “payment received” events with invoice IDs to the ERP.
- Auto-close rules marked invoices paid when full face value arrived; partials created exceptions queues.
- Refund API integrated with the ticketing system so approved cases generated an outbound SPEI automatically under dual control.
- Daily FX report summarized conversions, spreads, and realized EUR inflows for CFO review.
With those pieces in place, the collections cycle became predictable and auditable.
Lessons learned
- Virtual accounts beat free-text references. They shrink reconciliation work and block misapplied funds.
- Refund UX matters. Instant domestic refunds turned into a customer-trust accelerator and cut downstream disputes.
- Decouple payer experience from treasury decisions. Let customers pay locally; optimize FX and repatriation behind the scenes.
- Treat data fields as a product. Invoice, reference, and tax fields should satisfy enterprise AP systems from day one.
- Review alerts with your provider regularly. Thresholds that look sensible on paper often need tuning once real volumes arrive.
Where this model extends next
After stabilizing MXN, the same playbook can replicate to other corridors with robust local rails—PIX in Brazil, SPEI’s neighbors via regional partners, or instant rails in the UK and EU. The company’s internal blueprint now treats “local first, cross-border second” as the default for B2B bank transfers, while keeping card rails for small tickets and recurring card-friendly customers.