Quick Answer

For August 2026, confirm your obligations with official sources and schedule each with an internal date, responsible person, reviewer, and evidence. The 17th is common but not universal; regime, obligation, and RFC can change the applicable date and list.

Organize August 2026 with responsible parties, internal cutoffs, and evidence for SAT, IMSS, DIOT, CFDI, and Tax Mailbox.

Verify Before Filing

Dates and obligations depend on the taxpayer. Check the official calendar and current tax status before using this dashboard.

August Operational Dashboard

FrontPreparationResponsibleClosing Evidence
FilingsCFDI, banks, and papersAccountingAcknowledgment and payment
DIOTVAT by supplierTaxAcknowledgment and reconciliation
IMSS/SIPAREMovements and contributionsPayrollLine and payment
Tax MailboxPeriodic reviewComplianceLog and response

August Checklist

  • Confirm active obligations in the certificate and tax file.
  • Assign a responsible person and backup for each obligation.
  • Set internal cutoff before the official deadline.
  • Gather CFDI, bank statements, payroll, suppliers, and affiliation movements.
  • Save filing, acknowledgment, payment slip, and proof of payment.

From the official calendar to the team dashboard

  1. Extract obligations from the taxpayer’s file.
  2. Cross-check dates with SAT, IMSS, and official sources.
  3. Define information and review cutoffs per obligation.
  4. File and pay with operational margin.
  5. Close each task only when the file is complete.

Four calendar mistakes

  • Copying a generic calendar without validating active obligations.
  • Confusing the official date with the internal preparation date.
  • Marking as completed without saving acknowledgment and payment.
  • Leaving the Tax Mailbox without a responsible person during vacations.

What you must confirm before using any calendar

In August, monthly filings, social security payments, payment complements, DIOT reviews, and Tax Mailbox communications often coexist. Not all apply to every taxpayer, and the date may depend on regime, obligation, or the sixth digit of the RFC.

The correct list is obtained from each taxpayer’s file and cross-checked with the official calendar. This tool works as a preparation dashboard, not as a substitute for individual obligation consultation.

How to turn dates into an operational calendar

If a filing is due on the 17th, the team should not start on the 16th. Define internal cutoffs: complete information, reconciliation, review, authorization, and submission. The official date is the external limit; your internal date should allow time to correct differences and obtain acknowledgments.

A useful calendar not only shows deadlines: it shows who prepares, who reviews, what evidence is missing, and when it must be internally closed.

Fintax

Frequently Asked Questions

Does everything expire on the 17th?

No. It is a common reference for certain obligations, but you must check regime, type of filing, and official calendar.

What date should I put in my internal calendar?

A date before the deadline that allows for reconciliation, review, authorization, filing, and correction without working at the last minute.

What evidence proves compliance?

Keep the filing, acknowledgment, payment slip, proof of payment, and working papers explaining the calculation.

Sources and further reading

Consult official sources: SAT tax calendar, IMSS SIPARE, RMF 2026.

To complete the process within Fintax, review: monthly filings and acknowledgments guide, Tax Mailbox routine, SIPARE review.

What to do now

Turn this review into a file with responsible person, date, source, and evidence. If there is a material difference, a past-due obligation, or a decision that changes the calculation, validate the case with your accounting responsible before filing, canceling, or paying.