As of August 1, 2026, SAT eliminated the downloadable software for DIOT filing. Only the new online platform on sat.gob.mx is accepted — including for late filings of previous periods.
The DIOT in 90 seconds: what SAT actually does with that information
The DIOT (Declaración Informativa de Operaciones con Terceros) is the monthly informational return through which you report to SAT, supplier by supplier, how much VAT moved in each purchase transaction. Its legal basis is Article 32, fraction VIII of the VAT Law (LIVA) and Article 31 of the Federal Tax Code (CFF).
SAT does not use it merely as a filing record. It cross-references DIOT data against three data sources: the CFDIs your suppliers issued to your RFC, your monthly VAT declaration (where you declare creditable VAT), and the DIOT submissions your own suppliers made reporting you as their client. When those three sources do not align, the system generates an alert — which can turn into a formal requirement or a tax audit.
In plain terms: the monthly VAT payment says how much you owe; the DIOT says where that VAT comes from. They are two separate obligations and one does not substitute the other.
Who must file the DIOT — and who is exempt
| Taxpayer type | DIOT required? | Legal basis |
|---|---|---|
| Individual — Business & Professional Activities (PFAE general), prior income > $4M MXN | ✅ Yes | Art. 32-VIII LIVA |
| Individual — Business & Professional Activities (PFAE), prior income ≤ $4M MXN | ❌ Exempt | Art. 32-VIII LIVA, last paragraph |
| Individual — RESICO | ❌ Exempt | Art. 113-E LISR + RMF 2026 |
| Individual — Rental income, prior income ≤ $4M MXN | ❌ Exempt | Art. 32-VIII LIVA, last paragraph |
| Corporation — General regime | ✅ Yes (with exceptions) | Art. 32-VIII LIVA |
| Corporation — RESICO | ❌ Exempt during the fiscal year | Art. 206 LISR + RMF 2026 |
| Newly-created company | ❌ Exempt first fiscal year | RMF 2026 rule 4.5.1 |
| Corporation with prior-year ISR < $300,000 MXN | ❌ Exempt | RMF 2026 rule 4.5.1 |
| Taxpayer with no activity in the period | ⚠️ File DIOT with zeros | Art. 32-VIII LIVA |
What changed in the new DIOT platform in August 2026
Until July 2026, the DIOT could be filed via downloadable software, the SAT online portal, or a .txt file upload. Since August 1, 2026, SAT made the new online portal the only accepted method — the old software was disabled, even for filing back-periods.
Key changes in the new platform:
- 54 fields per supplier (versus 32 in the previous system) — more granular transaction classification
- Real-time RFC validation — the system checks the LCO (List of Taxpayers with Questionable Transactions) as each supplier RFC is entered
- Partial pre-fill — for some fields, SAT pre-loads data from CFDIs received with your RFC during the period
- Bulk .txt upload up to 40,000 records per file
- Integrated electronic signature — the acknowledgment is signed and recorded directly in the portal
Step by step: how to file the DIOT on the new SAT platform
What to prepare before opening the portal
- A list of all your suppliers for the period with their complete RFC (12 or 13 characters)
- Total VAT paid to each supplier, classified by rate (16%, 0%, exempt)
- VAT withholding amounts (if applicable)
- Identification of foreign supplier transactions (reported differently — type 05)
- Your valid e.firma or SAT password for authentication
Step 1 — Access the system
Go to sat.gob.mx → "Declaraciones" → "Declaración Informativa de Operaciones con Terceros (DIOT)." Log in with RFC + SAT password or e.firma. Select the tax year and monthly period you are declaring.
Step 2 — Choose filing method
Two options: Manual entry (for fewer than 15–20 suppliers) or bulk .txt upload (for large supplier volumes). The .txt format is specified in Annex 8 of the current RMF and requires exactly 54 fields per supplier record.
Step 3 — Enter supplier data
For each supplier, select the type of third party:
- 04 — Domestic supplier: individual or corporation with RFC in Mexico
- 05 — Foreign supplier: without permanent establishment in Mexico, no RFC
- 15 — Global transactions: small expenses without CFDI (taxis, markets, petty cash)
Step 4 — VAT fields per supplier
The key VAT fields to complete per supplier: non-creditable VAT at 16%, creditable VAT at 16%, VAT at 0%, exempt transactions, withheld VAT, and VAT on imports. After entering all suppliers, verify that the totals align with your monthly VAT payment for the same period.
Step 5 — Submit and save the acknowledgment
The system generates a receipt with an operation number after submission. Save it as part of your monthly tax file — it is your proof of compliance.
The 5 DIOT errors SAT detects automatically
1. Creditable VAT in DIOT exceeds VAT declared in the monthly IVA return for the same period. If your DIOT reports $80,000 of creditable VAT but your IVA declaration for the same month shows only $60,000, the $20,000 gap is interpreted as improper credit.
2. Incorrectly entered supplier RFC. One wrong character prevents SAT from cross-referencing the data with the CFDI issuer. The new platform validates RFC in real time for manual entries, but .txt files are imported as-is and errors remain.
3. Supplier on SAT's blacklist (LCO). If a supplier appears on the List of Taxpayers with Questionable Transactions (Art. 69-B CFF) and you have creditable VAT from their invoices, SAT can challenge that credit even if the CFDI is formally valid. The new DIOT 2026 platform alerts you in real time if a supplier's RFC is on the LCO.
4. Not reporting foreign suppliers correctly. Payments to foreign services (cloud hosting, SaaS software, Google or Meta advertising, international consulting) generate VAT on imported services (Art. 24 LIVA) — even without a local CFDI. That import VAT must appear in the DIOT under supplier type "05 — Foreign supplier."
5. Filing DIOT with zeros when activity did occur. If SAT has CFDIs registered to your RFC as recipient during the period, a "zero transactions" DIOT creates an automatic discrepancy flag.
DIOT and foreign taxpayers in Mexico
If your company has foreign suppliers — tech services, consulting, digital marketing platforms — each payment abroad may generate VAT on service imports (Art. 24 LIVA) that must be declared in the DIOT even without a local CFDI. If your company pays royalties or licenses to a foreign parent, those have a specific transaction type in the DIOT plus ISR withholding obligations under Title V.
For companies with international operations or cross-border supplier relationships, getting the DIOT right requires understanding both Mexican VAT law and — if a tax treaty applies — the interaction with the double taxation agreement. The Nexoconsult team works specifically with foreign-owned businesses and international taxpayers in Mexico — this type of situation is where early specialist input prevents expensive corrections later.
Frequently asked questions about the DIOT
What is the DIOT and what is it used for in Mexico?
The DIOT (Declaración Informativa de Operaciones con Terceros) is a monthly informational return that VAT taxpayers in Mexico must file. Its purpose is to report to SAT the detail of operations carried out with suppliers: how much VAT was transferred (IVA trasladado), how much was withheld and how much was credited. The legal basis is Article 32, fraction VIII of the VAT Law (LIVA) and Article 31 of the Federal Tax Code (CFF). SAT cross-references DIOT data against issued and received CFDIs to detect mismatches between declared VAT and VAT reported by your suppliers — discrepancies trigger formal requirements or tax audits.
Who is required to file the DIOT in Mexico and who is exempt?
Required to file: all taxpayers with VAT-taxable activities (individuals under the Business and Professional Activities regime, corporations under the general regime) who had operations with suppliers during the period. Exempt: (1) RESICO taxpayers — both individuals and corporations under the Régimen Simplificado de Confianza are relieved from filing DIOT; (2) Individuals whose prior-year income did not exceed $4,000,000 MXN from Business, Professional or Rental activities; (3) Newly-created companies during their first fiscal year; (4) Corporations whose prior-year ISR was under $300,000 MXN. When in doubt: not filing when you are obligated costs far more than confirming your status with a specialist.
When is the DIOT due and what is the monthly deadline?
The DIOT must be filed no later than the last business day of the month immediately following the period being reported. For example: July 2026 operations must be declared by August 31, 2026. If the last day falls on a Saturday, Sunday or official holiday, the deadline moves to the next business day. There is no automatic extension for any reason — SAT applies the fine from day one of delay. Since August 2026, filing is done exclusively on the new online SAT platform: the old downloadable software is no longer available, even for late filings of prior periods.
How much is the fine for not filing the DIOT in Mexico in 2026?
The fine for not filing or filing late is between $14,880 and $29,750 MXN per month of non-compliance, per the updated Miscellaneous Tax Resolution (RMF) 2026. In case of repeat violation, the fine doubles: $29,760–$59,500 MXN. This applies per declaration — if you have missed three months, you face three separate fines. Additionally, if the DIOT omission is linked to improper VAT credits, SAT can disallow the credit and demand payment of the VAT plus surcharges (1.47% monthly in 2026) plus the omission penalty (55%–75% of the unpaid tax). Voluntary correction before receiving a formal SAT requirement reduces the fine to 20% of the maximum amount.
How do you file the DIOT on the new SAT 2026 platform?
Since August 1, 2026, the DIOT is filed exclusively at sat.gob.mx → "Empresas" (or "Personas físicas") → "Declaraciones" → "Declaración Informativa de Operaciones con Terceros (DIOT)." You need RFC + SAT password or e.firma to log in. Two filing methods: (1) Manual entry — directly on screen, suitable for small supplier volumes; (2) Bulk upload — via a .txt file with a 54-field structure, for reports with multiple suppliers (up to 40,000 records per file). For each supplier you report: their RFC, type of third party (domestic/foreign/global), transaction type, value of activities, non-creditable VAT paid, creditable VAT paid, VAT paid on imports, withheld VAT and other relevant fields. The system generates an acknowledgment with an operation number that serves as your filing receipt.
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