Beyond the Devaluation Fear: How Indexed Tariffs, Currency Sweeps, and Offshore Escrow Protect Your African Infrastructure Returns

This article is in BOH Infrastructure’s 2026 Sovereign Risk Outlook series. The full Outlook establishes that risk in Africa is overwhelmingly a perception problem rather than a structural one. This briefing focuses on the credit enhancement instruments that translate that argument into bankable transactions.

Executive Summary

African infrastructure investment carries a reputation for currency risk that has kept billions of dollars of capital on the sidelines. This briefing argues that the reputation is largely a structuring problem, not a market problem. The projects that have suffered from currency devaluation were not victims of an uninvestable continent. They were victims of financial structures that ignored a known and manageable risk.

The core problem is the FX mismatch: infrastructure projects in Africa typically earn revenue in local currency while servicing debt in US dollars or euros. When the local currency depreciates, the revenue stays flat but the cost of debt service rises. At significant depreciation levels, this mismatch becomes a solvency issue.

BOH Infrastructure addresses this through four primary instruments. Currency Sweeps automatically convert local currency revenues to hard currency at regular intervals, preventing the accumulation of FX exposure over time. Offshore Escrow Accounts, held in jurisdictions such as Mauritius or London, place debt service reserves beyond the reach of domestic capital controls and government intervention. Local Currency Financing eliminates the mismatch at source by matching the debt currency to the revenue currency, and is more cost-competitive than headline interest rates suggest once currency depreciation is properly modelled. Indexed Tariffs, the most technically sophisticated of the four, embed automatic tariff adjustment clauses into PPP agreements and offtake contracts, so that when the currency moves, the project’s hard-currency revenue is preserved without renegotiation.

Critically, all four instruments must be structured during project development, before lenders are engaged. The window for effective currency de-risking is narrow, and it closes at financial close. Investors and sponsors who treat currency risk as a financing problem rather than a structuring problem consistently arrive at that window too late.

In 2023, Nigeria’s naira lost nearly 40% of its value against the US dollar in the space of twelve months. In Ghana, the cedi had already shed more than half its value the year before. For infrastructure investors watching from London, New York, or Singapore, these headlines confirmed what many already believed: Africa is too volatile, the currencies too unpredictable, the returns too fragile to justify the exposure.

That conclusion is understandable. It is also, in most cases, the wrong one.

Currency volatility in African markets is real. But the deals that failed, the projects that hit financial distress when the naira moved, the returns that evaporated when the cedi weakened, did not fail because Africa is uninvestable. They failed because they were structured as if the currency would stay stable. The risk was always there. It simply was not managed.

The investors who stayed in, and who continue to book strong risk-adjusted returns from African infrastructure, did something different. They built the currency risk into the structure from day one. They did not hope for a stable exchange rate. They designed their projects not to need one.

This briefing covers the four primary instruments for doing exactly that: Currency Sweeps, Offshore Escrow Accounts, Local Currency Financing, and Indexed Tariffs. Used individually, each one reduces FX exposure. Used in combination, which is how BOH Infrastructure approaches every transaction, they can effectively neutralise it.

The Real Problem Is Not the Currency. It Is the Mismatch.

Before examining the solutions, it is worth being precise about the problem. Currency risk in infrastructure is not simply that exchange rates move. Exchange rates always move. The specific risk that destroys returns in African infrastructure is the mismatch between how a project earns and how it borrows.

A toll road in Nairobi earns in Kenyan shillings. A power plant in Accra earns in cedis. A water treatment facility in Dakar earns in West African CFA francs. But the debt that financed their construction, arranged through international lenders or development finance institutions, is typically denominated in US dollars or euros. When the local currency depreciates, the revenue in local terms stays flat or grows, but the cost of servicing that hard-currency debt rises sharply. At 20% depreciation, the strain is manageable. At 40%, it is existential.

This is the FX mismatch problem. And it is not unique to Africa. Infrastructure projects in Latin America, Southeast Asia, and Eastern Europe have faced identical structural vulnerabilities. The difference is that in Africa, the mismatch tends to be larger, the hedge market thinner, and the advisory infrastructure less developed. The result is that many projects reach financial close with the mismatch unaddressed, not because it cannot be solved, but because it was not prioritised early enough.

The four instruments below address the mismatch at different levels of the capital structure. Understanding when to use each one, and how to combine them, is the practitioner’s core skill.

Instrument 1: Currency Sweeps

How a Currency Sweep Works

A Currency Sweep is a treasury mechanism embedded in the project’s financial structure, typically documented in the Common Terms Agreement between the project company and its lenders. Its function is straightforward: at a defined interval, usually monthly, local currency revenues above a specified operational reserve threshold are automatically converted to hard currency and transferred to a designated offshore account.

The sweep does not eliminate currency risk entirely. Conversion still happens at the prevailing spot rate on the sweep date, so the project is still exposed to short-term rate movements. What it does is prevent the accumulation of local currency exposure over time. Without a sweep, a project sitting on large local currency cash balances faces the risk that a sudden devaluation event, a central bank policy shift, an election, an IMF intervention, will wipe out months of earnings in a matter of days. The sweep removes that vulnerability by ensuring hard-currency conversion happens continuously, at regular intervals, before the exposure can grow.

Structuring the Sweep: What Gets Negotiated

The sweep structure involves several key negotiated parameters. The operational reserve floor, the amount of local currency retained in-country to cover day-to-day operating costs, needs to be set conservatively enough to cover genuine liquidity needs without leaving excess local currency on the table. Three months of operating expenditure is a common starting point, but the right figure depends on the project’s cost structure and local payment obligations.

Conversion timing is a more nuanced decision than it appears. Daily sweeps minimise exposure but generate higher transaction costs and can attract greater regulatory scrutiny. Monthly sweeps are simpler but leave the project exposed to within-month rate movements. Many well-structured projects use a hybrid approach: daily monitoring with a sweep trigger activated when the accumulated balance exceeds a defined threshold, regardless of the calendar date.

The Regulatory Dimension

The step that is most frequently underestimated, and most frequently responsible for delays, is obtaining regulatory approval for the sweep mechanism from the host country’s central bank. In Nigeria, this involves the Central Bank of Nigeria. In Kenya, the Central Bank of Kenya. In Ghana, the Bank of Ghana. These approvals are not automatic, and the timeline for obtaining them can run to several months.

BOH structures sweep mechanics during the bankability review phase, before term sheets are signed. Attempting to negotiate central bank permissions after lenders are at the table significantly complicates the process and drives up transaction costs. The time to secure these permissions is before financial close, which means it needs to be on the project development timeline from the beginning.

Instrument 2: Offshore Escrow Accounts

The Structural Firewall

An offshore escrow account is the most fundamental building block of currency de-risking in African infrastructure. It is not, strictly speaking, an FX hedging instrument, it does not fix or adjust the exchange rate. What it does is more important: it places the project’s critical financial reserves outside the jurisdiction of the host country, beyond the reach of capital controls, currency restrictions, or government intervention.

When a government faces a severe balance of payments crisis, its first instinct is often to restrict foreign currency outflows. Nigeria imposed strict FX controls during the naira crisis. Zimbabwe’s foreign currency restrictions have been documented extensively. Ethiopia has maintained complex foreign exchange queuing systems for years. In each case, projects that held their debt service reserves onshore found themselves unable to service their international debt, not because they lacked the funds, but because the funds were trapped.

An offshore escrow account, held in Mauritius, London, New York, or Singapore, cannot be reached by a domestic capital control order. It sits under international law, governed by the jurisdiction of the escrow bank, accessible only according to the contractual waterfall defined at financial close. It is the structural firewall between a government’s fiscal emergency and the project’s ability to meet its obligations.

The Three Core Account Types

Infrastructure projects typically operate with three distinct escrow account types, each serving a different function in the financial waterfall.

The Revenue Escrow Account receives all project revenues as the first point of collection. Before any cash is distributed to any party, including the project company’s operating account, it passes through the revenue escrow. This gives lenders visibility and control over the cash flow, and ensures that distributions to equity cannot happen if the project is not current on its debt service.

The Debt Service Reserve Account holds a pre-agreed liquidity buffer, typically equivalent to six months of projected debt service payments. This account is the lender’s insurance policy against temporary disruptions to project cash flow. If revenue is interrupted, by a dry season affecting a hydropower plant, by a government payment delay on a PPP, the DSRA provides the bridge. The DSRA balance is typically required to be maintained at all times, and a draw on the DSRA triggers a cash sweep covenant requiring the account to be replenished before any equity distributions are made.

The Distribution Account is the last stop in the waterfall. Equity sponsors can only access this account after all senior debt service has been paid, all reserve accounts are fully funded, and all covenant tests are met. This sequencing is the fundamental protection mechanism for lenders, and it is enforced offshore, where it cannot be interfered with domestically.

Jurisdiction Selection

The choice of offshore jurisdiction is not a cosmetic decision. Mauritius has emerged as the preferred jurisdiction for many African infrastructure transactions because of its network of Investment Promotion and Protection Agreements with more than forty African states, its double taxation treaty network, and its creditor-friendly legal environment. The Mauritian legal system is an internationally recognised blend of common law and civil law, and its courts have an established track record of enforcing commercial contracts.

For transactions with significant European or UK lender participation, a London-governed escrow is often preferred. For transactions with US development finance institution involvement, the US International Development Finance Corporation, for example, New York law is common. BOH advises on jurisdiction selection based on the host country’s bilateral treaty position, the governing law of the senior debt facility, and the composition of the likely lender group.

Instrument 3: Local Currency Financing

The Elegant Solution

The most structurally elegant response to the FX mismatch problem is to eliminate it at source. If a project earns in Kenyan shillings, borrow in Kenyan shillings. There is no devaluation risk on a debt instrument denominated in the same currency as the revenue stream. The mismatch does not need to be managed because it does not exist.

The near-universal objection to this approach is cost. Local currency lending rates in African markets are typically high. Kenya’s benchmark lending rate has run between 12% and 17% in recent years. Nigeria’s domestic borrowing costs have exceeded 20%. Compared to hard-currency DFI debt at 4–7%, local currency financing appears prohibitively expensive.

Rethinking the All-In Cost

This comparison is less straightforward than it appears, and the headline interest rate differential is frequently misleading.

Hard-currency debt at 6% does not cost 6% in local currency terms if the local currency depreciates. Over a ten-year infrastructure tenor in a market that has historically experienced 6–8% annual currency depreciation, the effective local-currency cost of a 6% hard-currency loan can exceed 14%. In markets with sharper depreciation, and several African currencies have experienced precisely that, the effective cost can be considerably higher.

The break-even calculation is simple: at what annual depreciation rate does local currency debt at 14% become cheaper than hard-currency debt at 6%? The answer, for most African currencies over a ten-year horizon, is a depreciation rate well within the range that central bank economists and currency strategists would consider a plausible base-case scenario. For currencies with structural current account deficits, managed exchange rate regimes, or large external debt burdens, that break-even is closer to a likely outcome than a tail risk.

Accessing Local Currency Capital

The practical challenge with local currency financing in Africa is not always cost, it is availability. Deep domestic bond markets and long-tenor local currency lenders are still developing in many markets, though the landscape is improving rapidly.

Kenya, Nigeria, and South Africa have developed domestic capital markets capable of absorbing substantial infrastructure bond issuances. The Nairobi Securities Exchange and the Johannesburg Stock Exchange have both seen infrastructure bonds listed and trading. African Development Bank instruments denominated in local currencies are increasingly available. Multilateral currency conversion facilities, notably the TCX Currency Fund, a specialist development finance vehicle designed specifically to provide local currency hedging and lending in frontier markets, offer additional tools for sponsors seeking local currency exposure.

BOH structures hybrid capital stacks that capture the cost advantage of hard-currency DFI concessional debt during construction, when the project is not yet generating revenue and FX mismatch is a secondary concern, while transitioning to local currency financing for the operational phase, when revenue is flowing and the mismatch exposure becomes critical. This approach requires careful structuring of the refinancing mechanism, but it is increasingly feasible as African capital markets deepen.

Instrument 4: Indexed Tariffs — The BOH Signature Approach

What an Indexed Tariff Is

An Indexed Tariff is a contractual mechanism, written into the PPP Agreement, the Power Purchase Agreement, or the offtake contract, that automatically adjusts the price charged for the infrastructure service based on predefined macroeconomic variables. It is not a renegotiation right. It is not a force majeure provision. It is an automatic, formulaic adjustment that requires no government approval to activate once it has been agreed at financial close.

The most common indexation variables are the bilateral exchange rate between the local currency and the project’s reference hard currency, local consumer price inflation, and, for energy projects, international fuel price indices. When the local currency depreciates against the reference currency, the tariff increases in local currency terms automatically, at the next billing cycle, preserving the investor’s hard-currency revenue in real terms.

For an electricity project, the mechanism works as follows. The base tariff is denominated in dollar-equivalent terms at financial close, for example, eight US cents per kilowatt-hour. Billing takes place in local currency at the prevailing spot rate on the billing date. If the local currency has depreciated by 20% since the base rate was established, the local-currency bill increases by 20% to preserve the dollar-equivalent revenue. The investor receives the same hard-currency value. The offtaker, typically a state utility, pays more in local currency terms.

For toll roads, indexation is typically applied to a composite basket that includes both CPI and FX components, reflecting the fact that the project’s costs include both imported capital equipment and locally-denominated labour and maintenance expenses.

Negotiating Indexed Tariffs: The Political Economy Challenge

The obvious challenge with indexed tariffs is political. A government counterparty signing a PPP Agreement is, in effect, agreeing to allow the price of a public service, electricity, water, road access, to rise automatically when its own currency weakens. In a devaluation scenario, precisely when the population is already experiencing economic stress, the tariff increases. This is a difficult political position for any government, and many have resisted indexed tariff clauses on exactly these grounds.

BOH’s advisory approach to this challenge is to reframe the negotiation entirely. The question is not whether the government should accept currency risk. The question is which currency risk scenario is worse: a tariff that adjusts automatically when the currency moves, or a project that defaults on its debt, ceases operations, and leaves a critical piece of national infrastructure dark or non-functional?

A 20% tariff increase in a devaluation scenario is economically painful. A power plant that cannot service its debt and is forced into renegotiation or receivership, leaving hospitals without electricity, factories without power, households in darkness, is catastrophically worse. When the choice is framed in those terms, most finance ministries and infrastructure regulators understand the logic of indexation. The task is to help them defend it to their own stakeholders.

The Consumer Protection Collar

To address the political defensibility challenge directly, BOH has developed a negotiation framework for indexed tariff clauses that includes what we refer to as a consumer protection collar. Rather than indexing the tariff with no ceiling, the clause caps the maximum upward adjustment that can be applied in any single billing period, typically quarterly, regardless of how sharply the currency has moved.

Where the exchange rate move exceeds the cap, the excess adjustment is deferred rather than forgiven. It accumulates in a stabilisation reserve account, funded during periods when the currency is stable or appreciating, and drawn down to cover the capped shortfall during devaluation episodes. Over the full project life, the investor’s hard-currency return is fully preserved. In any given quarter, the consumer faces a bounded adjustment rather than an uncapped shock.

This structure allows governments to accept indexation as a bankability requirement without facing a political scenario in which a sudden devaluation event translates immediately into a doubling of electricity bills. It makes the tariff clause politically defensible at the time of signing, and durable over the life of the concession.

Have you read?

Currency: Beyond the Devaluation Fear: How Indexed Tariffs, Currency Sweeps, and Offshore Escrow Protect Your African Infrastructure Returns

Credit: From B-Rated to Bankable: A Technical Guide to PRGs, MIGA Guarantees, and Blended Finance in African Infrastructure

Regulatory: Protecting Against the Stroke of a Pen: Stabilization Clauses, International Arbitration, and Regulatory Sandboxes in African PPPs

Technical: Ghost Projects and How to Avoid Them: AI Monitoring, Satellite Oversight, and the BOH Quality Assurance Process

Putting It Together: Which Instrument for Which Project?

No single instrument is the right answer for every transaction. The correct approach depends on the project’s revenue currency, the depth of the local capital market, the government counterparty’s appetite for indexation, and the composition of the lender group.

For projects with hard-currency offtake, an export-oriented industrial facility, a port handling foreign trade, a project with a DFI-backed offtaker, Currency Sweeps combined with offshore escrow are typically sufficient. The project earns in hard currency, the sweep captures it promptly, and the escrow protects the debt service reserve from domestic capital controls.

For projects with government offtakers and local-currency revenue, power plants selling to a state utility, toll roads with government concession payments, water treatment facilities billing a municipal authority, Indexed Tariffs are the core instrument. They need to be complemented by offshore escrow for the DSRA, and often by a Currency Sweep for day-to-day treasury management.

For projects in markets with sufficiently deep local capital markets, Kenya, Nigeria, South Africa, and increasingly Ghana and Morocco, Local Currency Financing should be evaluated seriously. In many cases, the risk-adjusted all-in cost is lower than it appears once FX depreciation is properly modelled into the hard-currency debt scenario.

For most transactions, the right answer is a combination of two or three instruments. A power project in Kenya, for example, might be structured with an Indexed PPA, a Mauritian-governed escrow holding a six-month DSRA, and a hybrid capital stack with TCX-supported local currency debt for the operational phase. Each element addresses a different dimension of the FX mismatch. Together, they produce a project that can withstand significant currency volatility without financial distress.

The Structuring Window Is Narrow

The most important practical point in this entire briefing is timing. Every one of the instruments described above is significantly harder, more expensive, and more contentious to negotiate once the project has reached term sheet stage. Central bank approvals for Currency Sweeps need to be on the project development timeline from the first feasibility study. Escrow jurisdiction selection shapes the governing law of the entire debt package. Indexed tariff clauses need to be embedded in the PPP Agreement before financial close, not inserted as amendments later.

Currency risk is often treated as a financing problem, something to be dealt with at the point of raising debt. In reality, it is a structuring problem. It needs to be addressed during project development, in the contract design phase, before any lenders are in the room. By the time a project is seeking term sheets, the structural framework should already be in place. The lenders are reviewing it, not creating it.

BOH Infrastructure’s involvement in transactions typically begins at pre-feasibility. That is the point at which currency structuring choices are most powerful and least costly. It is also the point at which most advisors are not yet engaged.

Conclusion

Currency risk in African infrastructure is not a reason to avoid the continent. It is a structuring challenge, a known, documented, well-understood problem with a set of known, documented, well-understood solutions. The projects that have been destroyed by currency devaluation were not destroyed by Africa. They were destroyed by inadequate structuring advice applied too late in the project lifecycle.

The instruments in this briefing, Currency Sweeps, Offshore Escrow, Local Currency Financing, and Indexed Tariffs, are not exotic or theoretical. They are standard features of well-structured African infrastructure transactions. What distinguishes BOH’s approach is not access to unusual instruments. It is the discipline of applying the right combination of instruments at the right stage of project development, structured around the specific risk profile of each transaction.

The currency will keep moving. The question is whether your project is built to move with it.

This article is part of BOH Infrastructure’s 2026 Sovereign Risk Outlook. The anchor report establishes why African infrastructure risk is a perception problem, and introduces the full BOH de-risking framework across all four risk dimensions. → Read the full 2026 Sovereign Risk Outlook

Currency structuring is one pillar of bankability. The second is credit enhancement. Read our full briefing on how MIGA guarantees, AfDB instruments, and blended finance make a B-rated project look like an A-rated investment. → From B-Rated to Bankable: A Technical Guide to PRGs and Blended Finance

Indexed Tariffs only hold their value if the PPP contract containing them is protected from unilateral government change. Read how BOH structures Stabilisation Clauses and International Arbitration seats to make indexation provisions contractually durable. → Protecting Against the Stroke of a Pen