The dispute

Heritage Oil & Gas v URA (Uganda Revenue Authority) arose out of a petroleum Production Sharing Agreement concluded between Heritage and the Government of Uganda.

The PSA contained an UNCITRAL arbitration clause for disputes that could not be amicably resolved. Heritage subsequently sold its interests in Ugandan petroleum assets to Tullow Uganda. Uganda Revenue Authority then issued capital gains tax assessments in connection with the transaction. Heritage challenged the assessment before the Tax Appeals Tribunal but also sought to have the dispute referred to arbitration under the PSA.¹

The resulting question was deceptively simple:

Can a contractual arbitration clause displace a statutory mechanism for determining tax liability?

The jurisdictional problem

Heritage argued that the Government had entered into the PSA voluntarily and that the Government and its statutory tax agency could not escape the arbitration clause. It relied on the statutory framework governing referral to arbitration and on the principle that an arbitral tribunal should ordinarily determine objections to its own jurisdiction.²

The Revenue Authority took a different position. Tax liability arose from statute rather than contract. The Tax Appeals Tribunal had been created under specific legislation to hear taxation disputes, and the contractual arbitration provision could not override that statutory jurisdiction.The High Court ultimately accepted the central point.

The Court’s reasoning

The Court distinguished between the contractual source of the petroleum relationship and the statutory source of the State’s taxing power. That distinction is crucial.

The existence of the Production Sharing Agreement (PSA) did not mean that every dispute touching the petroleum investment became contractual in character. Tax liability remained grounded in Ugandan legislation. The Court therefore treated taxation as a statutory matter rather than a contractual obligation capable of being displaced through private agreement.³

The Court also held that Section 5 of the Arbitration and Conciliation Act did not provide a mechanism for referring proceedings pending before the Tax Appeals Tribunal to arbitration. The provision referred to proceedings before a court and did not extend to the Tribunal in the manner argued by Heritage.⁴

The Court nevertheless corrected part of the Tribunal’s reasoning concerning the legal relationship between the Government and the Uganda Revenue Authority. The fact that the Revenue Authority was a separate statutory corporation did not, by itself, mean that the Government’s contractual obligations under the PSA could simply be ignored.⁵

The decisive point remained that taxation could not be converted into a contractual matter merely because the underlying investment agreement contained an arbitration clause.

Why the case matters for investment law

This case exposes a recurring tension in investment governance:investment agreements may be contractual, while many of the State’s powers affecting investments are statutory.

That distinction becomes particularly important in extractive industries. A petroleum investor may have contractual rights concerning exploration, production, stabilisation, cost recovery and dispute settlement. At the same time, the State retains statutory authority over taxation, environmental regulation, licensing and other matters of public law.

The mere existence of an arbitration clause does not necessarily transform those public-law powers into contractual obligations. This is particularly significant when viewed alongside treaty-based investment arbitration. International investment law can provide a further layer of protection, but the underlying question remains:

What type of legal obligation is actually being disputed?

The deeper question

Heritage Oil therefore provides a useful doctrinal distinction between:contractual protection, where the parties’ agreed obligations are central; and statutory public authority, where the State acts under legislative powers that cannot necessarily be modified by agreement.

For investment governance, the distinction has practical implications. If States do not clearly separate contractual commitments from statutory powers in investment agreements, later disputes may raise difficult questions over what has actually been consented to arbitration.

The case also demonstrates that arbitration clauses operate within a wider domestic constitutional and statutory framework. Consent to arbitration is important, but the legal character of the dispute remains decisive.

Case takeaway

Heritage Oil shows that a broadly worded contractual arbitration clause does not necessarily convert an exercise of statutory public power into a contractual dispute. That boundary becomes particularly important where petroleum investment agreements intersect with taxation.

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FOOTNOTES

1. Heritage Oil & Gas Ltd v Uganda Revenue Authority (Civil Appeal No 14 of 2011) [2011] UGCommC 97 (12 September 2011), pp 1–3. ↩︎
2. ibid, pp 5–8. ↩︎
3. ibid, pp 9–11. ↩︎
4. ibid, pp 9–10; Arbitration and Conciliation Act (Uganda), s 5. ↩︎
5. Heritage Oil & Gas Ltd v Uganda Revenue Authority (n 1), pp 8–10. ↩︎