An August with two open fronts: the usual ancillary obligations and the debut of IBS/CBS
The Brazilian Federal Revenue Service released the tax agenda for August 2026, with the official page updated on July 29, bringing the full calendar of declarations, bookkeeping records, and statements that companies and accounting firms need to comply with during the month. The timing is sensitive: beyond the usual volume of monthly filings, August is also the month in which the IBS and CBS fields stopped being optional in electronic tax documents, which increases the pressure on tax and IT teams that are already keeping an eye on the technical notes for NF-e, NFC-e, and NFS-e.
The dates that can't be missed
Below we've organized the month's main deadlines, according to the official Federal Revenue Service agenda.
August 10 — SisObraPrefWeb deadline:
Through SisObraPrefWeb, municipalities must send the Federal Revenue Service the list of construction permits and occupancy certificates ("habite-se") granted in July, information used to manage the National Construction Registry (CNO) and to oversee social security contributions in the construction industry.
August 14 — EFD-Contribuições: the bookkeeping record for June 2026 must be transmitted by this date, gathering information on PIS/Pasep and Cofins, under both the cumulative and non-cumulative regimes, as well as the Social Security Contribution on Gross Revenue when applicable.
August 17 — EFD-Reinf: the obligation for July 2026 is due on a Monday and gathers information on tax withholdings and other events not covered by eSocial; after closing, the data is automatically integrated into DCTFWeb, which requires extra attention to the consistency of the information before submission.
August 20 — A double-filing day: the Dirbi, referring to June, must be submitted by legal entities that benefited from tax incentives subject to declaration, and on the same date the PGDAS-D for July 2026 is due, used by companies under Simples Nacional to declare revenue and calculate taxes under the regime.
August 31 — The busiest day of the month: the last business day concentrates five commitments — DCTFWeb, DME, DOI, and DeCripto — plus filings applicable to both legal entities and, depending on each obligation, individuals.
Why cross-checking the data matters more than just meeting the deadline
A warning that often goes unnoticed is worth mentioning: filing on time, by itself, does not eliminate risks, since the information reported in EFD-Reinf, DCTFWeb, EFD-Contribuições, PGDAS-D, and other systems needs to be consistent with the company's tax, accounting, and financial records. Discrepancies between these systems are often exactly what triggers notifications and automatic cross-checks by the Revenue Service, so before submitting, it's worth reconciling the numbers across payroll, tax, and finance.
The backdrop: IBS and CBS no longer allow room for error
This calendar runs in parallel with another change that is already in effect: since August 3, electronic tax documents under the regular regime must have the IBS and CBS fields filled in, under penalty of rejection by the authorizing environment. This means the tax team is dealing simultaneously with two compliance fronts — the traditional agenda of ancillary obligations and the structural adaptation of issuing systems to the Tax Reform. Companies that integrate tax, accounting, and billing into a single environment tend to feel the weight of this overlap less, since data flows more consistently between modules.
How to organize the month in practice
- Build an internal calendar with each obligation, the person responsible, and the reference period;
- Reconcile EFD-Reinf, EFD-Contribuições, and DCTFWeb before submitting, since one feeds into the other;
- Set August 31 aside with extra attention — there are several filings due on the same date;
- Confirm whether product and customer records are already configured for the IBS and CBS groups, avoiding invoice rejection right in the middle of month-end closing;
- Keep track of any updates to the tax agenda throughout the month, since the Federal Revenue Service may revise deadlines.
This content is for informational purposes only and does not replace guidance from your accounting firm, which should assess your company's specific classification under each of these obligations.
If your team is feeling the weight of reconciling so many different systems within the same month, talk to Edoo and see how an integrated ERP can simplify this workflow.
August 2026 Tax Calendar: The Complete Deadline Roadmap to Keep Tax and Accounting Operations Running Smoothly