Taxpayers liable for the emissions tax — companies and entrepreneurs holding a GHG emission permit — file their return on Form PP EGESB, accompanied, in electronic form (PDF/JPG), by a verified emissions report, or an assessment by the competent authority where verification has not been carried out, together with any amended reports.
The return must also be accompanied by two additional forms: PIE, which reports GHG emission sources per individual installation, and OUE, which aggregates total emissions for the entire tax period. These forms are used to determine the taxable quantity of COâ‚‚eq.
The rulebook also specifically regulates the tax credit mechanism for investments in emission-reduction measures. Taxpayers must keep separate records of funds invested in each individual project, from which VAT is excluded where the taxpayer is entitled to deduct input VAT.
The return must be accompanied by Form PK-1 (an analytical overview of investments and projects) and Form PK-2 (a calculation of the total amount invested and the amount of credit used in the given period).
Rulebook on the Return for the Tax on Imports of Carbon-Intensive Products: the burden of proof falls on the importer
As regards the return for the tax on imports of carbon-intensive products, the return is filed on Form PP UUIP, which must be accompanied by Form UP — an overview of imported carbon-intensive products by supplier and tariff code, containing data on the quantity imported, the emission-determination method applied, emissions per unit of product, total and reference emissions, taxable emissions, the tax liability before reduction, and the amount of the tax credit.
A key element of this rulebook is the tax credit mechanism for the carbon price already paid in the country of origin of the product, calculated at the NBS mid exchange rate on the date of payment, and which may not exceed either the amount that would apply had the product been manufactured in Serbia, or the total tax liability stated in the return for that period. Evidence is provided through a CO₂eq emissions verification report and a confirmation from the competent authority of the country of origin that payment was made, with foreign-language documentation required to be translated by a certified court interpreter. In substance, this mechanism mirrors the logic of CBAM itself, which at EU level recognises a carbon price already paid outside the Union, thereby preventing the same product from being charged twice — first under the domestic tax, and then under the CBAM levy.
Rulebook on Data Submission: the role of the Customs Administration
The third rulebook introduces an obligation for the Customs Administration to submit data to the Tax Administration electronically, no later than the 10th of the month for the preceding month, drawn from the single customs declaration on imports of carbon-intensive products: the tariff code, description of goods, quantity, country of origin, customs value, the number and date of the declaration, and data on the importer and the customs procedure applied. This establishes a cross-verification mechanism between data on goods actually imported and what the taxpayer self-declares to the Tax Administration.
Significance of the Adopted Rulebooks
These rulebooks are not merely technical administrative acts; they determine how environmentally credible Serbia’s carbon taxation system will be in practice. The credibility of the entire model depends on the quality of verification: only independently verified emissions and savings can serve as the basis for establishing a tax liability, or for granting a tax credit. Without a reliable monitoring, reporting and verification (MRV) system, the “polluter pays” principle risks remaining merely declaratory, and the tax credit for “green” investments risks financing measures the taxpayer would have undertaken anyway, rather than incentivising genuine, additional emission reductions.
The detailed, installation-level reporting requirement (Form PIE) also represents a step toward a more transparent and comparable emissions-monitoring system in Serbia — one that could, in future, serve as a basis for further alignment with the EU Emissions Trading System (EU ETS).
However, several questions remain open in practice:
- The statutory deadline for adopting implementing regulations was 180 days from the adoption of the laws (December 2025), yet the rulebooks were not published until late July 2026 (almost seven months after the statutory tax obligation had already entered into application). It remains to be seen how this delay will be resolved with regard to the deadlines for filing the first tax returns and gathering the documentation required for the elapsed period.
- Will the methodology for determining reference emissions for imported products be fully aligned with the EU’s CBAM rules, given that any misalignment could lead to different calculations for the same product at national and EU level?
- Do the Tax Administration and the Customs Administration have the technical capacity for regular monthly exchange and cross-verification of large volumes of customs and tax data?
- The requirement that foreign-language documentation be translated by a certified court interpreter represents an additional administrative and financial burden for importers, particularly small and medium-sized enterprises, and raises the question of whether translations will be available within timeframes compatible with the tax calendar.
- How will the competent authorities supervise the work of the verification bodies issuing emissions reports, given that the quality of that verification directly determines both the amount of the tax liability and the amount of the tax credit?
The consistency with which these rulebooks are implemented — particularly with regard to the quality of emissions verification and the alignment of methodology with the European CBAM framework — will determine not only the fiscal functionality of the new system, but also its underlying environmental purpose: ensuring that the costs of pollution are allocated realistically and fairly, and that funds collected through green taxes are genuinely directed toward the decarbonisation of the economy.