Russia’s reduction of gas supplies to Bulgaria after the outbreak of the Ukraine conflict catalyzed Sofia’s search for alternative energy sources and supply routes. With limited liquefied natural gas (LNG) import capabilities, Bulgaria turned to Türkiye as a pivotal partner for its energy security. In 2023, an agreement was established between the Turkish Petroleum Pipeline Corporation (BOTAŞ) and Bulgargaz, allowing for the annual transfer of up to 1.5 billion cubic meters of natural gas over a span of 13 years. This strategic alliance was intended to curtail Bulgaria’s reliance on Russian energy while opening access to global LNG markets via Türkiye’s infrastructure.
The Shift in Perception of the Agreement
What was initially viewed as a strategic lifeline soon became perceived as a financial liability for Bulgaria. After just three years, both parties opted for a 15-month suspension of the contract instead of outright termination. The rising costs associated with the capacity guarantee proved to be burdensome for Bulgaria. Under the agreement, Bulgaria was obliged to pay not only for the gas it actually consumed but also for the reserved capacity, which in 2023 was seen as an insurance policy for energy security. However, it later emerged that much of the reserved capacity went unused. Despite this, BOTAŞ has yet to release an official statement confirming the extent of this unused capacity. This situation raises critical questions under energy law, particularly about the future viability of long-term contracts in an evolving market.
In 2025, Bulgarian Energy Minister Zhecho Stankov highlighted that terminating the agreement outright could incur costs exceeding 2 billion euros. Various estimations indicated that the contractual obligation could be around 4 billion Bulgarian lev, equating to roughly $2.3 billion. Thus, Bulgaria confronted a complex dilemma: maintain its contractual commitments while exploring avenues for renegotiation, using both political and legal strategies to reshape the agreement’s terms.
The Importance of Local Interconnections
The relationship between BOTAŞ and Bulgartansgaz extends beyond the initial commercial agreement. In January 2024, both countries’ transmission system operators formalized an interconnection agreement for the Strandzha Malkoclar border connection, which established a technical capacity of approximately 117.7 million kWh per day from Türkiye to Bulgaria. This connection is vital for Bulgaria’s long-term energy goals as it paves the way for LNG as well as Azerbaijani gas to reach Bulgaria and other parts of the region via Türkiye’s transmission network.
It’s essential to differentiate between the two agreements: the BOTAŞ-Bulgargaz pact is a long-term contract focusing on LNG access and transportation, while the BOTAŞ-Bulgartransgaz agreement pertains to operational interconnections at the border. This distinction becomes crucial when assessing Türkiye’s role in enhancing energy security in the Balkans. Despite the ongoing renegotiation of the BOTAŞ agreement, the strategic significance of gas flows through Türkiye remains evident.
A Temporary Retreat, Not a Withdrawal
On July 6, 2026, a key development unfolded. Following discussions between President Recep Tayyip Erdoğan and Bulgarian Prime Minister Rumen Radev, a protocol was signed to suspend the current commercial agreement for 15 months. Importantly, during this period, Bulgaria will only pay for the capacity it utilizes, relieving it of the financial burden associated with unused reserves. This temporary suspension does not signify termination; rather, it affords both parties a chance to reevaluate and renegotiate the agreement’s terms without incurring the penalties associated with a full exit.
The landscape of the energy market has changed significantly since 2023. What was once disregarded as excess capacity has taken on newfound value. The ongoing Russia-Ukraine conflict and instability in regions affecting gas supply chains have heightened the importance of maintaining flexible energy arrangements.
In conclusion, Bulgaria’s decision to freeze the BOTAŞ agreement illustrates a calculated move rather than a complete abandonment of energy ties with Türkiye. Instead, Bulgaria is strategically attempting to recalibrate its energy portfolio for improved flexibility and reduced costs. As Sofia diversifies its gas supply options, including increased access to Azerbaijani gas and LNG routes through Greece, Bulgaria seems to be enhancing its bargaining stance. The geopolitical landscape continues to evolve, presenting new challenges and opportunities. Therefore, the next 15 months of negotiations will be critical in determining how Bulgaria navigates its energy future amid these changing dynamics.