Single Foreign Trade Portal (Siscomex) releases new DUIMP version with IBS and CBS fields
Those who work with foreign trade have a relevant technical milestone this week. (cite index="31-1,31-3">The Federal Revenue Service will implement in production the adjustments that allow calculating CBS and IBS item by item in the import declaration, in accordance with Siscomex Import Notice No. 089/2026, published on August 19. Production rollout was scheduled for September 27, and a supplementary notice published days later brought important operational details for those who rely on the Single Portal on a daily basis.
The 9/26 blackout and the release of the new version
(cite index="22-1">In addition to Siscomex Import Notice No. 089/2026, it was announced that, after the resumption of the Siscomex Single Portal systems shutdown announced in Siscomex Systems Notice No. 016/2026, DUIMP registration would remain blocked until 11:59 PM on 9/26. (cite index="22-2">This block was due to the temporary unavailability of the banking network at the PCCE (Centralized Foreign Trade Payment). During the blackout window, (cite index="22-3">if a DUIMP registration attempt was made, the system would return the error message "Active Account – Not registered in the PCCE system", and (cite index="22-4">it would not be necessary to open an error ticket with SERPRO in these cases. (cite index="22-5">Starting at 12:00 AM on 9/27, DUIMP registration was released, already with the new version of the system.
Prior to that, (cite index="23-6,23-7">there was a scheduled shutdown of the Siscomex Single Portal systems on Saturday, September 26, from 2 PM to 6 PM, affecting modules such as DUIMP, DU-E, LPCO, Product Catalog, Customs Clearance, CCT, Tax Treatment, Centralized Payment, and Classif. IT teams that maintain automated integrations with the Single Portal needed to factor in this window in scheduled registration and transmission routines.
What changes in filling out the declaration
The changes are not just infrastructure-related. (cite index="29-4">Among the main changes are the requirement to report the state (UF) and municipality of the location of the consumption operation for each DUIMP item, filling in other taxes and duties owed until the goods are released, and changes in how the CST and cClassTrib codes are determined. This means that the information is no longer associated only with the operation as a whole, and now requires attention item by item.
One point that simplifies the tax team's work: (cite index="22-8,22-9">it will no longer be necessary to fill in the cClassTrib field in DUIMP items — the CST and cClassTrib codes for each item are now defined by the system based on the chosen legal grounds. Even so, it is essential to review the register of legal grounds used by the company, since an incorrect legal ground (FL) generates an equally incorrect automatic tax classification.
To reduce risk during the transition, the Federal Revenue Service allowed a margin of tolerance: (cite index="22-6,22-7">initially, some optional CBS/IBS Legal Grounds would not be available, being implemented throughout the week following the release's deployment, and registering a DUIMP with an inappropriate CBS/IBS FL due to lack of the correct option would not be grounds for penalty. This tolerance is temporary and should not be treated as a permanent exemption from review.
No collection yet, but data is already being captured
It's worth reinforcing for those in operations: (cite index="22-10">there will be no charging or collection of CBS/IBS before 01/01/2027. This confirms that 2026 remains the test year for the reform in imports, with (cite index="37-4">a test rate of 1% (0.1% IBS and 0.9% CBS) already applied to tax documents in general. Even without an immediate financial impact, correctly filling out the DUIMP already matters: the data captured now feeds the assisted assessment that actually takes effect in 2027, and registration errors tend to carry over into the following year.
Quick checklist for teams
Tax, accounting, and IT teams operating in foreign trade can use the coming days to: review the registration of the state (UF) and destination municipality for each recurring item in the operation; validate the parameterization of the legal grounds used in the company's imports; test ERP integration with the Single Portal considering the new mandatory fields; and monitor the production environment during the first registrations after 9/27, since some optional legal grounds were still being added the week following deployment.
This content is for informational purposes only and does not replace guidance from your accounting firm or a foreign trade specialist, who should assess the specific classification of each import operation.
If your company imports goods and wants its ERP already aligned with these Tax Reform changes, talk to Edoo.
DUIMP and Tax Reform: What Changes on 09/27/2026 and How to Prepare Tax, Accounting, and IT