Tullow Oil shares crash 50% after Ghana wins $196.5 million tax dispute

Shares of Tullow Oil Plc, a UK-based oil producer, plummeted by approximately 50% on Wednesday following Ghana's victory in a lengthy arbitration dispute over a $196.5 million tax assessment. The decline came after Tullow disclosed on September 30, 2026, that an International Chamber of Commerce tribunal had ruled in favor of Ghana's assessment, stating that the tax demand did not violate the company's petroleum agreements.

The controversy centered around insurance proceeds received by Tullow between 2016 and 2019 under its Business Interruption insurance policy. Tullow challenged the assessment through international arbitration following a December 2022 payment demand from the Ghana Revenue Authority. The tribunal upheld the $196.5 million corporate income tax assessment, which dates back to December 2022.

Tullow filed for arbitration in February 2023, expressing a willingness to reassess its options following further discussions with the Ghanaian government. Ghana's government affirmed its intent to implement the arbitration award, aiming to secure revenue while enabling Tullow to continue operating and investing. The ruling's impact was significant, as it coincided with Tullow's strategic focus on its high-value Ghana assets post-dissolution in markets like Gabon, Equatorial Guinea, Kenya, and Côte d'Ivoire.

The victory for Ghana underscores its efforts to boost government revenue, local value addition, and foreign-exchange reserves, providing an additional tool to enforce revenue claims from key oil producers.