Eustream

Slovakia – November 03, 2026 -- The EU Agency for the Cooperation of Energy Regulators (ACER) has found that Eustream's proposed gas transmission tariffs, which would raise charges by more than 50% midway through the current tariff period, do not comply with the EU Network Code on Harmonised Transmission Tariff Structures (NC TAR).

Eustream cites collapse in cross-system flows for mid-period change

Eustream, Slovakia's transmission system operator, proposed a new reference price methodology and tariffs for January 2026 to December 2027. The operator pointed to exceptional circumstances, specifically a large drop in cross-system flows. The plan combines a uniform postage stamp methodology with an ex-ante entry-exit split.

SHERIDAN, WYOMING - April 13, 2026 - The EU Agency for the Cooperation of Energy Regulators (ACER) has released its compliance assessment of Slovak gas transmission tariffs proposed by Eustream, Slovakia's transmission system operator, finding that key elements of the methodology fail to meet EU Network Code on Harmonised Transmission Tariff Structures (NC TAR) standards and issuing concrete corrective recommendations to the Slovak national regulator ÚRSO ahead of its final tariff decision.

What Eustream proposed

Eustream's proposed reference price methodology (RPM) covers the multi-year tariff period 2026-2027 and includes several substantive changes to current practice. The most consequential is a mid-period tariff revision that would increase charges by more than 70%, which Eustream justifies by citing exceptional circumstances - specifically, a large drop in cross-system gas flows that has materially reduced revenue recovery.

SHERIDAN, WYOMING - March 31, 2026 - Gas shippers and large energy users in Slovakia face a tougher tariff-planning environment in 2026 because ACER has found that key elements of the country's proposed gas transmission pricing framework cannot yet be confirmed as aligned with EU tariff rules, creating potential changes to cost recovery, cross-border trade conditions, and final regulatory decisions. ACER's report reviews the reference price methodology proposed by Eustream, Slovakia's transmission system operator, for the 2026-2027 multi-year tariff period and sets out where the Slovak regulator ÚRSO should tighten the approach before adoption.