Executive summary: five tax bodies, one trajectory
As of May 2026, the five major LATAM tax authorities — SUNAT, DIAN, SAT, ARCA, and SII — closed the basic-digitization phase of tax control and shifted to automated enforcement. Average SMB fines rose 30–40% year over year. Excel as a survival strategy stopped working.
The country-level headlines, one line each:
- Peru (SUNAT). SIRE moved from principales to medianos. The 2025 UIT = S/ 5,350 sets the base for fine calculations; the 2026 UIT decree publishes each December via the MEF.
- Colombia (DIAN). 2026 UVT ≈ COP $49,799. The documento soporte de adquisiciones (DSA) is now universal. RADIAN now holds more than 4 million registered invoices.
- Mexico (SAT). Carta Porte 3.1 is in full production. CFDI defect fines: MX$17,020 – MX$97,330 per document (CFF Art. 84).
- Argentina (ARCA). Former AFIP fully renamed: new domain, new forms, same CUIT. The February 2026 monotributo recategorization raised the revenue and social-contribution ceilings.
- Chile (SII). Law 21,713 is fully in force. New anti-avoidance rules (GAAR) and mandatory transparency for digital platforms now apply.
From 2022 through 2024, each regulator moved at its own pace. In 2026, all five finished basic digitization at the same time and entered an automated-enforcement phase that operates through fines. This is not rhetoric, it's operational. When a regulator sees a mismatch between SIRE and ledgers, between CFDI and payment complements, or in the RADIAN trail, it doesn't ask for clarification — it issues the assessment with the fine already calculated.
SMBs that ran parallel books through 2024–2025 — ERP on one side, Excel on the other, quarterly reconciliation — received the first wave of penalty resolutions in the first half of 2026. The pattern repeats across all five jurisdictions: automated cross-check → discrepancy → fine → administrative response → 60–90 days fighting for reduction or reversal.
If your SMB operates in one or more of these countries and still relies on manual audit to catch issues, this snapshot is your position.
Peru: SIRE goes universal, fines escalate
Since January 2026, SIRE (Sistema Integrado de Registros Electrónicos) is mandatory for every principal contribuyente and now extends to medianos. SUNAT does not frame SIRE as one more report — it replaces the Electronic Books (PLE). The Electronic Purchase Registry (RCE) and Electronic Sales Registry (RVIE) are generated on SUNAT's side from data the regulator already receives through CPE.
Base fines, anchored to the UIT (Tax Code Schedule of Infractions):
- Late PLE/SIRE filing: 0.6 UIT per period (~S/ 3,210 at 2025 UIT). The régimen de gradualidad grants up to 90% reduction if you self-correct before notification.
- CPE defect: between 0.3 UIT and 50% of the document value.
- Late GRE (Electronic Shipping Note): 25% of the transported goods' value, capped at 6 UIT.
The key trend: SUNAT lowered the threshold for automated cross-checks. What used to surface through selective audits in 2024 now gets caught by mass monthly reconciliation. The SUNAT 2026 hub keeps the operational matrix current.
Colombia: DIAN expands DSA, RADIAN, and electronic payroll
2026 UVT ≈ COP $49,799 sets the base for fines, the simplified-regime ceilings, and mandatory e-invoicing thresholds. What shifted in the first half:
- Documento soporte de adquisiciones (DSA) is now universal for any payment to a supplier without an invoice, regardless of amount or supplier regime.
- RADIAN — DIAN's registry for circulating electronic invoices — passed 4 million documents in May 2026. Registration remains voluntary, but it's effectively required in B2B chains where the buyer demands chain of custody.
- Electronic payroll tightens deductibility control by cross-checking against PILA. SMBs without electronic payroll lose salary expense as an income-tax deduction.
Base DIAN fines (Tax Statute Art. 651–657):
- Failure to issue an electronic invoice: 1% of the undeclared period's gross revenue.
- CUFE defect: up to 5 UVT per document.
- Late electronic payroll: ~5 UVT per worker per period.
The operational stack for Colombia is documented in the DIAN 2026 hub and the Odoo Colombia configuration with l10n_co.
Mexico: Carta Porte 3.1 in production, CFDI fines that hurt
Mexico is LATAM's most mature e-invoicing jurisdiction — and, as a consequence, the one with the harshest fines. CFDI 4.0 is now stable. The active front in 2026 is Carta Porte 3.1 for every goods transfer.
SAT fines for defective CFDI (CFF Art. 81 fr. XLII and Art. 84):
- Document missing required data: MX$17,020 – MX$97,330 per document.
- Carta Porte with errors: equivalent scale, multiplicative per transfer.
- Uncancelled CFDI: 55%–75% of the document value.
The 2026 Resolución Miscelánea Fiscal (RMF), published in December 2025 and amended in Q1, moved three fronts:
- Payment-complement rules — invoice ↔ payment reconciliation.
- REP (electronic payment receipt) update.
- Carta Porte expansion to more operations, including light-tonnage transport.
SMBs running an external PAC without ERP integration took a wave of automated cancellations in the first half: SAT accepts the document and rejects it 24–72 hours later for complement-version mismatch. SAT CFDI Real Ops documents how to block the pattern before it lands.
Argentina: ARCA replaces AFIP, monotributo recategorized
By mid-2026, ARCA (Agencia de Recaudación y Control Aduanero) fully replaced AFIP across forms, systems, and references. This is the Milei administration's structural reform of tax administration. CUIT and fiscal keys stayed the same; old afip.gob.ar links redirect to arca.gob.ar.
February 2026's monotributo recategorization raised annual revenue and social-contribution ceilings across all categories A–K. The exact thresholds live in ARCA's Categories Table, updated through indexation.
Electronic invoicing remains mandatory for nearly all regimes. The Simplified Regime for Gross Income Tax (RSIIB) progresses unevenly at the provincial level: one version in Buenos Aires, another in Córdoba, another in CABA. SMBs operating across multiple provinces must review the Multilateral Agreement (Convenio Multilateral).
The operational detail of the change lives in AFIP/ARCA Monotributo 2026.
Chile: Law 21,713 — anti-avoidance, digital platforms, full DTE
The Tax Modernization act (Law 21,713, December 2024) is fully in force. As of mid-2026:
- GAAR (General Anti-Avoidance Rule): SII gained expanded authority to recharacterize business structures under anti-avoidance rules.
- Mandatory transparency for digital platforms: Uber, Rappi, Cornershop, Airbnb, and similar players must report active-merchant data.
- DTE (Documento Tributario Electrónico): covers every category — factura, boleta, shipping note, credit note, export document.
May 2026 UTM ≈ CLP $68,000. DTE non-issuance fines range from 50% to 500% of the operation value, capped in UTA (Tax Code Art. 97). The SII 2026 hub tracks the country-specific matrix.
Cross-jurisdiction patterns and common SMB mistakes
Four shared trends emerge from the five country cuts:
- Automated enforcement. Regulators stopped asking for clarification; they fine based on the cross-check result. Defense is built through post-hoc administrative response, not by avoiding scrutiny.
- Document unification. SIRE in PE, RADIAN in CO, CFDI 4.0 in MX, ARCA in AR, the DTE suite in CL — all five converge on the same model: a centralized, real-time registry of every business document.
- SMBs at the center. Large enterprises are already compliant. Focus shifted to mid-market and small firms, where the under-collection is largest.
- Cross-border data sharing. OECD CRS, Pillar Two, ARCA–DIAN exchange, SAT–SUNAT through CIAT — data doesn't stay in one jurisdiction.
The most common mistakes we see in SMBs that migrate late:
- Ignoring version changes. CFDI 3.3 → 4.0, Carta Porte 2.0 → 3.1, RADIAN protocol, SIRE format. They stay on old versions because "it works" — until the first audit.
- Manual reconciliation across SIRE / RADIAN / RVIE / CFDI. This is not a temporary fix. It's an unstable process where discrepancies compound month over month and ultimately blow up the cross-check.
- Base ERP without localization. Odoo, SAP, or Oracle without
l10n_pe,l10n_co,l10n_mx,l10n_ar, orl10n_clwon't deliver a single correct invoice to SUNAT, DIAN, SAT, ARCA, or SII. National CTA, series, digital certificates, and XML format all need configuration. - Blind reliance on PAC or OSE. The digital-signature provider (PAC in Mexico, OSE in Peru, certified provider in Colombia) is a single point of failure. If it doesn't validate a field, the rejection comes back 24–72 hours later.
- Skipping electronic payroll in DIAN. The most frequent mistake in Colombia: "payroll isn't an invoice." It is, in deductibility terms. Without electronic payroll, salary expense doesn't reduce income tax.
Anonymous case: Lima/Bogotá retail chain, Q1 2026 compliance audit
Regional chain with 5 locations in Lima and 3 in Bogotá, ~USD 2.5M/year revenue. It ran local invoicing systems in Peru and Siigo in Colombia, with no shared accounting layer.
Situation in January 2026. SUNAT ran SIRE against ledgers: 12% drift for 2025. DIAN, in parallel, issued a notice for Q4 2025 electronic payroll. Response deadline: 15 business days on both fronts.
What got done (8 weeks). Migration to Odoo with l10n_pe and l10n_co. SIRE 2025 reconstructed via retroactive update. Electronic payroll connected via a DIAN-certified provider. Parallel reconciliation against PLE/RVIE/RCE, closing line-by-line discrepancies.
Result. SUNAT fines reduced ~90% through régimen de gradualidad (timely response + correction). DIAN fines reduced ~50% through voluntary correction. Combined fine savings: ~USD 45,000. Monthly compliance cycle dropped from 18 to 4 person-days.
It's not that the regulator is being harsher. It's being faster. What used to take 9 months to arrive as an observation now lands in 30 days as a fine.
H2 2026 checklist: what to have ready before December
What's coming in the second half:
- Peru: final SIRE extension to small contributors; new decree with 2027 UIT.
- Colombia: 2027 UVT (calculated from October inflation).
- Mexico: draft 2027 RMF by November, typically with new complements.
- Argentina: August 2026 monotributo recategorization.
- Chile: 2026 Operación Renta, the first one under the new GAAR.
The operational minimum to reach December clean:
- ERP with current localizations, validated in production — not in sandbox.
- Quarterly internal audit that reconciles ERP data against regulator responses.
- Documented administrative-response process to handle notices within 15 business days.
- Verified email channel with the regulator: SUNAT sends notices to the electronic fiscal domicile — if no one watches it, the clock still runs.
Frequently asked questions
What's the fine for not filing SIRE in Peru?
The base fine is 0.6 UIT per period (~S/ 3,210 at 2025 UIT = S/ 5,350). The régimen de gradualidad grants up to a 90% reduction if you self-correct before SUNAT notification.
Did ARCA fully replace AFIP?
Yes. Since 2024–2025, every official system, form, and reference migrated to ARCA. CUIT and fiscal keys stayed the same. Old afip.gob.ar links redirect transparently to arca.gob.ar.
Is Carta Porte 3.1 mandatory for every goods movement in Mexico?
It applies to every federal-highway transfer and most categories on local roads. Exceptions narrowed in 2026 — verify against RMF Annex 20 and SAT's quarterly updates.
What is RADIAN in Colombia, and do I need to register?
RADIAN is DIAN's registry for circulating electronic invoices. Registration is voluntary for the holder, but effectively required if you want to negotiate invoices or work with large buyers that demand chain of custody.
How much does it cost to bring an SMB into LATAM 2026 compliance from scratch?
For 1–2 countries at ~100 transactions/month on a base ERP: USD 3,000 – 15,000 initial project, plus USD 300 – 1,200/month for maintenance. Multi-country with ERP↔PAC↔bank integration starts at USD 25,000+.
Can the migration wait until 2027?
Technically yes. Each month of delay adds another month of automated-notice risk. Regulators already issue "missing-data" reports based on their own data, without asking the taxpayer first.
Where do I find current fine amounts?
Official sources: SUNAT Schedule of Infractions (Tax Code annex), DIAN Tax Statute Art. 651–657, SAT CFF Art. 81–84, ARCA Law 11,683 Art. 38–49, SII Tax Code Art. 97.