Nigeria's Marginal Energy Bets $225m on Sierra Leone Oil
A Nigerian explorer bets on frontier oil
Sierra Leone signed a $225 million petroleum licence agreement with Nigeria-based Marginal Energy on April 23, 2026. The deal grants offshore exploration and production rights in a basin that has barely produced oil commercially. The investment covers seismic surveys and a drilling programme, per Reuters.
This is a bet on a frontier market. But for Nigeria's tax authority, it raises a quieter question: can FIRS collect its share of whatever Marginal Energy finds?
What FIRS doesn't track
Nigerian companies are investing abroad more often. Oil service firms, exploration juniors, and even fintechs have set up offshore structures. Yet FIRS has a patchy record on taxing foreign income. Transfer pricing audits remain inconsistent. The agency still relies on self-reported data from companies with complex cross-border operations.
The marginal tax rate in Sierra Leone is 25%, below Nigeria's 30%. If Marginal Energy books profits in Sierra Leone, or routes them through a holding company in another low-tax jurisdiction, Nigeria may see little revenue. Given the $225 million commitment, the potential tax loss is substantial.
FIRS has been busy with other things: chasing informal sector traders, trying to plug VAT leakages, and clearing a backlog of unprocessed refunds that has frustrated businesses. The agency's 2024 scorecard showed it missed its revenue target by 12%. The research context confirms this deal is about reviving Sierra Leone's offshore sector, but says nothing about tax implications for Nigeria. That silence is itself a risk.
The second-order effect
If Marginal Energy strikes oil, Nigeria's treasury gains nothing directly. The company's Nigerian shareholders might repatriate dividends, but those are taxed at just 10% withholding. Compare that to the 30% corporate income tax if the same profits were earned inside Nigeria. The incentive to keep revenue offshore is obvious.
FIRS could tighten transfer pricing rules for natural resource companies. It could require advance pricing agreements for all cross-border oil service deals. It could even impose a minimum tax on foreign earnings of Nigerian firms. None of these are on the agenda publicly.
Sierra Leone wins a shot at oil revenue and jobs. Marginal Energy's shareholders win a cheap entry ticket to a frontier basin. Nigeria loses tax base and gains nothing but bragging rights that a local company is expanding.
Investors should watch FIRS's next quarterly report. If it shows a dip in oil-sector tax receipts, this deal may be part of the story. The risk is not that Marginal Energy fails, it's that it succeeds, and Nigeria's taxman has no seat at the table.