TheDigger Intelligence Unit
Every year, banks roll out glossy CSR reports, sponsor community projects, hand out loyalty rewards, and still post record profits — while the interest paid to ordinary savers barely moves the needle. This piece breaks down, factually, how that math works: globally, in Nigeria specifically, and why the gap between what banks pay you and what they earn off you is built into the model itself.
Section 1: The Global Mechanics — How Banking Actually Works
At its core, a bank’s business is borrowing cheap and lending dear. Deposits — savings and current accounts — are, from the bank’s accounting perspective, the cheapest source of funding available to it, cheaper than borrowing from bond markets or other institutions. Every fraction of a percentage point a bank pays less for its funding generally widens its net interest margin, although that margin must still cover operating expenses, regulatory costs, loan losses, taxes, and capital requirements before becoming profit.
Deposits remain the backbone of bank funding, but modern banking is more complex than the old textbook “money multiplier” model. Banks use customer deposits as a relatively stable and inexpensive source of funding, while creating new loans subject to regulatory capital requirements, liquidity rules, reserve requirements, credit demand, and their own assessment of risk. When banks extend loans, those funds often circulate through the financial system and may become deposits elsewhere, supporting additional lending over time. The result is that the banking system can generate a much larger stock of loans and deposits than the initial amount of cash placed into any one account, although this process is constrained by regulation and market conditions rather than occurring mechanically.
The “net interest margin” is the primary profit engine. This is simply the gap between the average interest rate a bank earns on loans and securities, and the average rate it pays out on deposits. It is the single largest revenue line for most commercial banks worldwide, ahead of fees or investment income.
Beyond the spread, banks have several other income streams that don’t touch depositor interest at all:
Transaction and account fees (maintenance charges, ATM fees, card fees, wire transfers)
Treasury and securities income — banks park idle funds in government bonds and other instruments that pay guaranteed yields
Non-interest/”ecosystem” income — payments processing, wealth management, insurance, brokerage, advisory services on mergers and share issues
Why depositors have so little leverage. Switching banks is inconvenient, and safety (deposit insurance, familiarity, salary accounts) keeps most savers put regardless of rate. Borrowers, meanwhile, often have fewer alternatives to bank credit, especially for mortgages and business loans. That asymmetry — a captive depositor base on one side and often-captive borrowers on the other — is what allows the spread between the two rates to stay wide without much competitive pressure to close it.
Where community spending and rewards fit. CSR budgets, sponsorships, and customer loyalty programmes are typically a small fraction of total profit — treated by banks as marketing and reputational spend, and in some jurisdictions, encouraged or required by regulators as part of financial-inclusion or sustainability frameworks. Academic research on Nigerian banks specifically has found that heavier CSR spending is sometimes associated with slightly lower short-term profitability ratios, not the reverse — reinforcing that it is philanthropy funded out of profit, not a profit driver in itself.
Section 2: The Nigerian Numbers — What the Data Actually Show
Nigeria offers an unusually transparent, and unusually stark, illustration of the global pattern above, because the Central Bank of Nigeria (CBN) publishes the relevant rates directly.
The policy backdrop. As of the CBN’s July 2026 Monetary Policy Committee meeting, the benchmark Monetary Policy Rate (MPR) stood at 26.5%, held steady after a 50-basis-point cut in February 2026 — the first reduction in the current tightening cycle that began in 2023. The Cash Reserve Ratio, which determines how much of every deposit a commercial bank must set aside rather than lend out, was retained at 45% for deposit money banks (16% for merchant banks, and a steep 75% on non-Treasury Single Account public sector deposits).
What savers actually earn. CBN regulation requires banks to pay savers a minimum of 30% of the MPR on regular savings accounts — a rule introduced in 2022 (up from just 10% previously). In practice, CBN’s own published data in 2026 showed most tier-one banks paying savings customers around 8% per annum, with some institutions offering as little as 2–4.25%. Ordinary current/transactional savings accounts at several banks were reported at just 1–4%.
What borrowers actually pay. Over the same period, CBN’s Money Market Indicators showed the average prime lending rate — the rate offered to the most creditworthy customers — sitting near 19%, while the average maximum lending rate charged to ordinary borrowers ranged between roughly 33% and 35% through most of 2026. Individual banks disclosed even wider spreads: one merchant bank’s maximum lending rate reached 60%, and several commercial banks’ ceilings sat in the 38–48% range.
Why are lending rates so much higher than savings rates? Part of the difference reflects profit, but part reflects the costs and risks of lending. Banks must account for borrowers who default, maintain regulatory capital, comply with prudential rules, operate branches and digital infrastructure, invest in cybersecurity and technology, and pay taxes. In high-inflation and high-interest-rate environments such as Nigeria’s in recent years, those costs and risks become even more significant. Even after accounting for them, however, the gap between average deposit rates and lending rates remains the principal source of commercial bank earnings.
Put plainly: a saver earning 8% while the bank turns around and lends at 19–35%+ represents a spread of anywhere from 11 to over 25 percentage points on the same naira — before counting fees, treasury income or FX gains.
Why the spread is not all profit. The difference between lending rates and deposit rates—often called the interest spread or net interest margin—is not pure profit. It helps cover expected loan defaults, funding and operating costs, regulatory compliance, capital requirements, taxes, and returns expected by shareholders. In Nigeria’s high-inflation, high-interest-rate environment, these costs and risks are particularly significant. Even after accounting for them, however, the spread remains the principal source of earnings for most commercial banks.
The profit numbers. Nigeria’s major banking groups posted some of their strongest results on record through 2025 and into 2026. Access Holdings reported a 2025 profit before tax of over ₦616 billion; GTCO delivered roughly ₦900 billion; Zenith Bank, UBA, and others posted comparable or higher figures, with the top seven to ten listed banks collectively earning well over ₦1 trillion in after-tax profit in a single quarter of 2026 alone. Analysts and CBN commentary have attributed much of this to elevated lending rates, treasury/government-securities income, and non-interest “ecosystem” revenue (payments, digital fees), rather than to any dramatic surge in the volume of new lending to the real economy — credit to manufacturers, for instance, was reported to have contracted over the same period.
Where community spending sits in that picture: CBN’s Nigerian Sustainable Banking Principles (introduced 2012) require banks to report on social and environmental initiatives, and major lenders now publish annual sustainability disclosures covering health financing, education programmes, and SME support. These are real and often substantial in naira terms — but they are a line item drawn from a much larger profit pool, not a competing use of the same funds that would otherwise go to depositors. Nothing in CBN’s savings-rate regulation ties minimum depositor interest to how much a bank spends on CSR.
Section 3: Connecting the Dots — Why the Gap Persists
Put the two pictures together, and the pattern is consistent, not coincidental:
The regulatory floor on savings interest is deliberately low. Even where regulators mandate a minimum (Nigeria’s 30%-of-MPR rule is one of the more interventionist examples globally), that floor still leaves a wide gap to the lending rate, because the rule caps what banks must pay, not what they may charge borrowers.
Deposits support lending across the banking system in ways that are not always visible to individual savers. A customer’s ₦100,000 deposit provides part of a bank’s funding base, while new lending creates additional deposits elsewhere in the financial system as borrowers spend the money they receive. Over time, this expands the overall stock of bank credit and deposits, although the process is constrained by capital rules, liquidity requirements, reserve requirements, borrower demand, and banks’ willingness to take risk. The result is that banks can generate interest income from a loan portfolio that is substantially larger than the cash initially deposited by any individual customer.
Fees and treasury/FX income are additive, not substitutive. They don’t reduce the pressure to keep deposit rates low — if anything, they make it easier for a bank to absorb periods (like FX volatility) when one income stream weakens, without ever needing to compete harder for depositor loyalty by raising savings rates.
CSR, rewards, and community investment are downstream of profit, not a drain that justifies low deposit rates. They are funded from the same pool that produces record profits and dividends — they don’t explain why savers get 8% while borrowers pay 30%+; that gap exists regardless of how much or little a bank gives back.
The Bottom Line for Readers
The “peanuts” paid to depositors is not a sign that banks have little to share — it’s a structural feature of the lending business itself. The spread between what banks pay savers and what they charge borrowers is, for most commercial banks in Nigeria and around the world, the single largest source of earnings. That spread must first absorb operating costs, regulatory requirements, taxes, and credit losses before becoming profit, but it remains the foundation of the commercial banking business model.
Sources: Central Bank of Nigeria publications and data, including Monetary Policy Committee communiqués and Money Market Indicators; 2025–2026 annual reports and financial statements of major Nigerian banks
