In a final award dated 22 September 2026 (the “Award”), the arbitral tribunal in the dispute between Tullow Ghana Limited (“TGL”) and the Republic of Ghana (“Ghana”) rejected TGL’s contractual challenge to a USD 393.1 million tax-and-penalty assessment. The London-seated arbitration proceeded under the 2021 Rules of Arbitration of the International Chamber of Commerce (“ICC”) before Prof. Albert Jan van den Berg, as president, Dr. Michael Pryles and Mr. J. Christopher Thomas (the “Tribunal”).[1]
The Award draws an important distinction between a tribunal’s jurisdiction to hear a contractual dispute concerning taxation and its power to review a tax authority’s assessment. While the Tribunal accepted that TGL’s claims fell within its jurisdiction, it was not prepared to reassess the Ghana Revenue Authority’s (“GRA”) decision de novo. Instead, it adopted a deferential approach to the GRA’s exercise of discretion and ultimately found no breach of the Petroleum Agreements. The Award therefore does not establish a general rule on the taxation of business-interruption insurance proceeds in Ghana.[2]
Facts
TGL, an indirect wholly owned subsidiary of Tullow Oil plc (“Tullow PLC”), conducted petroleum operations in Ghana under two agreements: the agreement dated 22 July 2004 concerning West Cape Three Points (the “WCTP Agreement”) and the agreement dated 10 March 2006 concerning Deepwater Tano (the “DWT Agreement”; together, the “Petroleum Agreements”). The Jubilee field extended across both contractual areas. The Petroleum Agreements were governed by Ghanaian law, consistently with applicable rules of international law.[3]
Article 12 of the Petroleum Agreements limited the taxes and other fiscal charges that Ghana could impose in connection with petroleum operations and the sale and export of petroleum. It nevertheless permitted income tax at a rate of 35%, in accordance with the Petroleum Income Tax Law, 1987, PNDCL 188 (“PITL”), subject to provisions allowing for a lower rate. Article 24 of the DWT Agreement provided for arbitration and was extended to the unitised Jubilee field through a contractual acknowledgement in 2009. Article 24.10 also addressed the suspension of certain contractual obligations when a matter was referred for resolution.[4]
The dispute arose following damage to the turret bearings of the Kwame Nkrumah Floating Production Storage and Offloading vessel (the “FPSO”) in 2016, which disrupted production and increased operating costs. TGL operated the FPSO and co-owned it with its joint-venture partners. Between 2016 and 2019, Tullow PLC received USD 561,559,991 under the business-interruption cover of the group’s Energy Package Policy 2013 (the “Policy”). These payments (the “Insurance Proceeds”) were separate from the amounts recovered under TGL’s hull-and-machinery insurance.[5]
A key point of disagreement concerned whether TGL was entitled to the Insurance Proceeds. Although the Policy’s general definition of an insured included Tullow PLC and its subsidiaries, TGL maintained that the business-interruption cover protected Tullow PLC’s own financial interest. A loss-adjuster’s final report dated 14 August 2019 (the “Report”) identified TGL as the insured, but a subsequent clarification dated 14 October 2022 stated that Tullow PLC should have been identified instead. The Report was provided to the GRA on 18 October 2022. While the GRA had been aware of certain insurance receipts since 2018, it had not previously received the Report.[6]
On 1 December 2022, the GRA issued a tax assessment against TGL comprising USD 196,545,996.85 in income tax and an additional 100% penalty of the same amount (the “Penalty”), bringing the total to USD 393,091,993.70 (the “Assessment”). TGL challenged the attribution of the Insurance Proceeds to it, the imposition of the Penalty and the timeliness of the Assessment in respect of the 2016 and 2017 tax years.[7]
TGL issued a notice of dispute on 30 December 2022. Shortly afterwards, on 13 January 2023, the GRA commenced recovery proceedings before Ghana’s High Court, which it subsequently withdrew on 30 January 2023. TGL filed its request for arbitration on 13 February 2023. During the proceedings, a separate award issued on 24 December 2024 in an earlier branch-profits-tax dispute between TGL and Ghana (the “BPT Award”) became relevant to the question of whether Ghana could raise certain jurisdictional objections in the present arbitration.[8]
Issues
The Tribunal first had to determine whether it had jurisdiction to hear TGL’s claims. In particular, it had to consider whether Ghana had agreed to arbitrate disputes with TGL individually, rather than only with all private participants in the unitised Jubilee field, and whether TGL’s claims arose under the Petroleum Agreements or instead concerned matters of domestic tax law falling outside the arbitration agreement. This also raised the question of whether the claims were arbitrable. The Tribunal further had to consider whether the earlier BPT Award prevented Ghana from raising certain jurisdictional objections under the doctrines of issue estoppel or abuse of process.[9]
On the merits, the main question was whether the Assessment breached Article 12 of the Petroleum Agreements. More specifically, the Tribunal had to determine whether the income tax had been imposed in accordance with the PITL, whether the Penalty fell within the scope of Article 12 and, if so, whether it satisfied the relevant statutory requirements, and whether the Assessment was time-barred for the 2016 and 2017 tax years. The parties also disagreed on the degree of deference the Tribunal should afford the GRA’s decision and the applicable standard of proof. Finally, the Tribunal had to consider whether the GRA’s recovery proceedings breached Article 24.10 of the DWT Agreement, given that they had been commenced and withdrawn before TGL requested arbitration.[10]
Holding
The Tribunal found that it had jurisdiction to hear TGL’s contractual claims under the Petroleum Agreements. It also held that Article 12 required Ghana not only to apply the agreed income-tax rate but also to comply with the relevant provisions of the PITL. However, this did not mean that the Tribunal could reassess TGL’s tax liability from scratch. Instead, it adopted a deferential approach when reviewing the GRA’s exercise of its discretionary powers, assessing whether its decision was reasonable. The Tribunal also confirmed that the applicable standard of proof was the ordinary civil standard of the balance of probabilities.[11]
Although TGL succeeded on jurisdiction, its claims ultimately failed on the merits. The Tribunal found that the income-tax assessment did not breach Article 12 and that the Penalty fell outside the scope of that provision. It also rejected TGL’s argument that the Assessment was time-barred, finding that the Report provided new information that allowed the GRA to issue an assessment beyond the ordinary limitation period. As for the GRA’s recovery proceedings, the Tribunal found no breach of Article 24.10 of the DWT Agreement, as those proceedings had been withdrawn before TGL requested arbitration. Importantly, the Tribunal did not determine whether the Penalty itself was valid under section 33 of the PITL.[12]
On costs, the Tribunal ordered each party to bear its own legal expenses and half of the arbitration costs, amounting to USD 585,500 each out of a total of USD 1,171,000. The Award did not require TGL to pay the assessed tax debt, as Ghana had not pursued its counterclaim for recovery of the Assessment. The Tribunal’s final decision was therefore limited to determining whether Ghana had breached its contractual obligations and allocating the costs of the arbitration.[13]
Reasoning
Jurisdiction: Contractual Tax Claims and Issue Estoppel
The Tribunal first considered Ghana’s objections to its jurisdiction. Ghana argued that TGL could not bring arbitration proceedings on its own because the contractual arrangements governing the unitised Jubilee field required the participation of all private parties. Applying English law, as the law of the arbitral seat, the Tribunal found that Ghana was prevented from raising this objection by the doctrine of issue estoppel. Although Ghana had not raised the same argument in the earlier proceedings, the BPT Award had already accepted jurisdiction over a dispute between TGL and Ghana individually. That decision necessarily rested on the existence of consent to arbitration between those two parties, which Ghana could not challenge again.[14]
However, the Tribunal did not consider that the BPT Award prevented Ghana from raising its other jurisdictional objections. Unlike the first objection, these concerned matters that had not been conclusively determined in the earlier proceedings or arose in a different factual and legal context. In particular, the Tribunal noted that the BPT Award’s observations on jurisdiction over a potential limitation dispute under the PITL had not been necessary to the outcome of that case. Accordingly, the remaining objections were not barred by issue estoppel or abuse of process.[15]
Nevertheless, the Tribunal ultimately rejected those objections as well. It found that the Petroleum Agreements imposed contractual obligations on Ghana concerning taxation and that disputes over compliance with those obligations fell within the scope of the arbitration agreement. The fact that resolving TGL’s claims required consideration of Ghanaian tax legislation did not make them purely statutory disputes. The Tribunal could therefore determine whether Ghana had complied with its contractual obligations without assuming the role of the GRA or a domestic tax court. Since both parties also agreed that claims arising under the Petroleum Agreements were arbitrable under Ghanaian and international law, the Tribunal concluded that it had jurisdiction to hear TGL’s claims.[16]
Standard of Review in Ghana Tax Arbitration: Deference and the Balance of Probabilities
Before turning to the merits of the Assessment, the Tribunal considered the extent to which it could review the GRA’s exercise of its discretionary powers under section 5 of the PITL, which deals with tax avoidance. The Tribunal acknowledged that it was neither a Ghanaian tax authority nor a constitutional court, and that taxation was a sovereign function entrusted to domestic institutions. It therefore considered it necessary to respect the role of those institutions when reviewing the GRA’s decision. Having examined the relevant Ghanaian authorities, the Tribunal adopted a deferential standard of review based on reasonableness.[17]
Under this approach, the Tribunal’s task was not to determine whether it would have reached the same conclusion as the GRA, but rather whether the Assessment fell within the range of reasonable outcomes. However, the Tribunal distinguished this degree of deference from the applicable standard of proof. It rejected Ghana’s argument that TGL should be required to meet a higher evidential threshold and confirmed that the ordinary civil standard of the balance of probabilities continued to apply.[18]
The Tribunal also noted that TGL had not pursued the available procedures for challenging the Assessment before the competent Ghanaian authorities. Although the Petroleum Agreements did not require TGL to exhaust local remedies before commencing arbitration, the absence of findings from the relevant domestic institutions further limited the Tribunal’s review of the Assessment.
Income Tax Assessment Under Article 12: Anti-Avoidance and Insurance Proceeds
Ghana argued that Article 12 of the Petroleum Agreements merely established the applicable income-tax rate of 35%. The Tribunal disagreed, finding that such an interpretation would give little effect to the requirement that income tax be imposed in accordance with the PITL. It therefore concluded that Article 12 required Ghana not only to apply the agreed tax rate but also to comply with the relevant provisions of the PITL. This meant that TGL could challenge the Assessment on contractual grounds, although the Tribunal ultimately rejected that challenge on the merits.[19]
The Tribunal then examined the statutory basis for the Assessment. Although the GRA had not expressly referred to section 5 of the PITL, the Tribunal accepted that the Assessment was based on sections 1, 2 and 5. In reaching this conclusion, it noted that the GRA had repeatedly described the insurance arrangement as involving tax avoidance or tax fraud, which was sufficient to establish its reliance on the anti-avoidance provision. The Tribunal also rejected TGL’s argument that the GRA was required to follow a particular sequence or form of reasoning when applying those provisions.[20]
The Tribunal further found that the information available to the GRA provided a reasonable basis for attributing the Insurance Proceeds to TGL’s operations in Ghana. In particular, the Policy’s definition of an insured extended to subsidiaries, TGL co-owned and operated the FPSO, and the Report repeatedly identified TGL as the insured party that had suffered the relevant losses. The Tribunal also noted that the revenue being compensated would ordinarily have arisen in Ghana and been subject to taxation there. Moreover, when the GRA issued the Assessment, it did not have access to the detailed evidence concerning English insurance law that TGL subsequently presented during the arbitration.[21]
However, the Tribunal did not go so far as to determine whether TGL was itself insured under the Policy or legally entitled to the Insurance Proceeds under English law. Even if TGL’s interpretation of the Policy was correct, this did not necessarily resolve the separate question of whether the arrangement, under which compensation for losses arising from Ghanaian operations was paid to Tullow PLC, could reasonably be treated as a form of tax avoidance. The Tribunal’s conclusion was therefore limited to finding that the GRA’s Assessment was not unreasonable in light of the information available to it, without independently determining TGL’s entitlement to the Insurance Proceeds.[22]
Tax Penalties Under Article 12: Limits of Contractual Protection
TGL argued that the Penalty fell within the scope of Article 12 of the Petroleum Agreements because it qualified as an “other impost”. It also maintained that the GRA had failed to comply with the requirements of section 33 of the PITL, including what TGL considered to be a requirement for a summary conviction before a penalty could be imposed. The Tribunal, however, began by considering whether the Penalty was covered by Article 12 at all, rather than examining its validity under Ghanaian tax law.[23]
The Tribunal concluded that Article 12 did not extend to the Penalty. In its view, the expression “other impost” referred to fiscal charges similar to taxes, duties and fees, rather than penalties imposed for non-compliance. This interpretation was supported by other provisions of the Petroleum Agreements, which expressly mentioned penalties where the parties intended to address them. Since Article 12 contained no such reference, the Tribunal found that the Penalty fell outside its scope and that its imposition did not constitute a breach of the Petroleum Agreements.[24]
Having reached this conclusion, the Tribunal considered it unnecessary to determine whether the Penalty related to petroleum operations or whether it had been imposed in accordance with section 33 of the PITL. The Award therefore did not establish that the Penalty was valid under Ghanaian tax law, but only that its imposition did not breach Article 12 of the Petroleum Agreements.[25]
Limitation Periods for Tax Assessments in Ghana: The New Information Exception
The Tribunal also considered whether the Assessment had been issued within the applicable statutory time limits. It accepted that Article 12 required Ghana to comply with the limitation provisions of the PITL and that an assessment issued outside those limits could amount to a contractual breach. Under section 18(3) of the PITL, the ordinary four-year limitation periods for the 2016 and 2017 tax years had expired in 2020 and 2021, respectively. The GRA, however, did not issue the Assessment until December 2022.[26]
The Tribunal noted that these time limits were subject to exceptions under section 79(2) of the Internal Revenue Act, 2000, Act 592 (the “IRA”), which permitted assessments to be issued after the ordinary limitation period in cases involving fraud, gross or wilful neglect, or the discovery of new information concerning the tax payable. TGL argued that the discovery of new information could justify a later assessment only where that information had been deliberately concealed or withheld through fraud or neglect. The Tribunal rejected this interpretation, finding that the provision established separate grounds for extending the assessment period. As a result, the discovery of new information did not depend on proof of fraud or misconduct.[27]
The Tribunal then considered whether the Report qualified as new information. Although the GRA had been aware of certain insurance receipts since 2018, it had not received the Report until October 2022. The Report contained further information concerning the identity of the insured party and the losses covered by the Policy, which had not previously been available to the GRA. The Tribunal therefore found that the Report constituted new information within the meaning of section 79(2) of the IRA, allowing the GRA to issue the Assessment after the ordinary limitation periods had expired. On that basis, it rejected TGL’s limitation argument without deciding whether TGL had also been guilty of gross or wilful neglect.[28]
Tax Recovery Proceedings Under Article 24.10 and Allocation of Arbitration Costs
The Tribunal also considered whether Ghana had breached Article 24.10 of the DWT Agreement by commencing recovery proceedings against TGL. Under that provision, certain contractual obligations were suspended once a dispute had been referred for resolution. The Tribunal, however, distinguished between issuing a notice of dispute, which initiated negotiations between the parties, and formally referring a matter to arbitration or a sole expert. Since the GRA had both commenced and withdrawn its recovery proceedings before TGL filed its request for arbitration, the Tribunal found that Article 24.10 had not been breached.[29]
As for costs, the Tribunal took into account that both parties had achieved some degree of success. While TGL had prevailed on jurisdiction, Ghana had successfully defended the claims on the merits. The Tribunal also considered that neither party’s position had been frivolous and that both had conducted the proceedings efficiently. In light of these circumstances, it decided that each party should bear its own legal costs, while the costs of the arbitration would be shared equally.[30]
Conclusion
The Award highlights both the scope and the limits of contractual protections against taxation. Although Article 12 required Ghana to comply with the relevant provisions of the PITL, the Tribunal’s role was to determine whether Ghana had breached its contractual obligations, rather than reconsider the GRA’s tax assessment. Applying a deferential standard of review, the Tribunal ultimately rejected TGL’s claims.[31]
The decision also offers lessons for drafting petroleum agreements. In particular, it highlights the importance of expressly addressing penalties and specifying when contractual obligations are suspended following a dispute. It further demonstrates the significance of the information available to tax authorities, as the Report provided the basis for rejecting TGL’s limitation argument.[32]
As noted in commentary on the decision, the Award should not be interpreted as establishing that business-interruption insurance proceeds are generally taxable in Ghana or that the Penalty was valid under domestic law. The Award must also be understood in the context of the historical tax legislation and specific contractual arrangements applicable to TGL, rather than as a statement of Ghana’s current tax law. Its broader significance lies in recognising that contractual tax protections can be enforced through arbitration, while respecting the authority of domestic tax institutions.[33]
[1] Tullow Ghana Limited v. Republic of Ghana, ICC Case No. 27585/AB/CPB, Final Award, 22 September 2026, paras. 1-2, 8-13, 552.
[2] Id. paras. 365-374, 398-405, 447-448.
[3] Id. paras. 12-13, 100-105.
[4] Id. paras. 11, 107-114.
[5] Id. paras. 117, 120-123, 144-147.
[6] Id. paras. 126, 135-138, 148-149, 184-185, 188, 508-509.
[7] Id. paras. 192-195, 426.
[8] Id. paras. 14, 196-197, 212, 287-298.
[9] Id. paras. 210-212, 285-286.
[10] Id. paras. 375-377, 460, 483, 518-528.
[11] Id. paras. 365-374, 398-405, 432-435, 487-491.
[12] Id. paras. 448, 473-475, 516-517, 526-530.
[13] Id. paras. 378, 546-552.
[14] Id. paras. 299-302, 320-332.
[15] Id. paras. 333-355.
[16] Id. paras. 365-374.
[17] Id. paras. 393-403.
[18] Id. paras. 391, 402-405.
[19] Id. paras. 432-436.
[20] Id. paras. 437-441.
[21] Id. paras. 442-446.
[22] Id. paras. 445-448.
[23] Id. paras. 449-453, 460-463.
[24] Id. paras. 464-473.
[25] Id. paras. 474-475.
[26] Id. paras. 487-494.
[27] Id. paras. 495-502.
[28] Id. paras. 503-517.
[29] Id. paras. 526-529.
[30] Id. paras. 542-551.
[31] Id. paras. 398-405, 432-448.
[32] Id. paras. 469-475, 503-517, 526-529.
[33] MSL Business School, Tullow Ghana Limited v Republic of Ghana, TaxLawGH, 30 September 2026, https://www.taxlawgh.com/ghana-tax-case-tullow-ghana-v-republic-of-ghana-icc-2026 (last accessed 15 October 2026), “Detailed TaxLawGH analysis”, sections A-D; TGL v. Ghana, paras. 447, 473-475.