If you’ve ever sat down to research where to invest your money in Nigeria’s fixed-income market, you’ve probably run into the same fork in the road: Treasury Bills or Bonds? Both are issued and backed by the Federal Government, both are considered some of the safest investments available locally, and both show up constantly in conversations about “risk-free” returns. But they are built differently, taxed differently, and suited to different kinds of investors — and getting that distinction right can meaningfully change what you walk away with. 

Here’s a clear breakdown of how they actually work; 

What Are Treasury Bills? 
Treasury Bills (T-Bills) are short-term debt instruments issued by the Central Bank of Nigeria (CBN) on behalf of the Federal Government, with tenors of 91, 182, or 364 days. They’re sold at a discount —The interest on the principal is paid upfront and the full investment sum is received at maturity, hence your interest is effectively paid in advance rather than in instalments. 
For example, if you invest in a 364-day T-Bill at a 16% yield, you pay the face value less the yield today and receive the full amount at maturity, with the difference being your return. 

What Are FGN Bonds? 

Federal Government of Nigeria (FGN) Bonds are medium- to long-term debt instruments issued by the Debt Management Office (DMO), typically running from 2 years (FGN Savings Bonds) up to 10, 20, or even 30 years for standard FGN Bonds. Unlike T-Bills, bonds pay periodic coupon interest — usually semi-annually for standard FGN Bonds, or quarterly for FGN Savings Bonds — at a fixed rate set when the bond is issued, with your principal returned in full at maturity. 

 This structure makes bonds a tool for predictable, stable income rather than a single lump sum at the end. 

Yield: Which Pays More? 

This is where the discussion gets interesting, and where a lot of investors get caught up with simply chasing the “bigger” returns. 

This year began with T-Bills stop rates ranging from 15%-18% per annum, we also witnessed a historic session where the 364-day bill priced lower than the shorter-term bills. The stop rates have been trending lower as the CBN’s rate-cut cycle stays in motion. 

FGN Bond yields have moved in a similar direction — strong yields above 17% at the start of the year, compressing into the 14%–16% range as the year progressed, with the benchmark 10-year bond yield settling around 15% by late May. 

At first glance, T-Bills often look like the higher-yielding option — and on a gross basis, they frequently are. But yield alone doesn’t tell the full story, because tax treatment changes the picture considerably. 

Tenor and Time Horizon 
This is the most fundamental structural difference between the two instruments. T-Bills are short-dated by design —you are never locked in for more than a year, and you can choose 91, 182, or 364 days depending on your investment goals and targets. This makes them a natural fit for short-term goals: an upcoming expense buffer, a business float, or simply investing idle cash you don’t want sitting in a low-yield savings account. Bonds, by contrast, are built for the long game. FGN Savings Bonds run 2–3 years, while standard FGN Bonds can extend to 10, 20, or even 30 years. If you’re investing for a goal that’s years away — retirement, a child’s education, long-term wealth preservation — bonds let you lock in a fixed rate for a much longer stretch, insulating you from having to reinvest at potentially lower rates down the line. 

Liquidity: Can You Get Your Money Out Early? 
Both instruments can be sold before maturity in the secondary market, but the experience differs. T-Bills are highly liquid relative to their short tenor — because the wait to maturity is already measured in months, exiting early via the secondary market is generally straightforward, though you may sell at a small premium or discount depending on where rates have moved since you bought in. Bonds are liquid in principle but carry more interest rate risk over a sale before maturity, simply because more time remains for rates to move for or against you. A bond bought when yields were high will lose secondary-market value if yields fall further, and vice versa. If you’re not confident you can hold to maturity, this is worth weighing carefully before committing to a longer-dated bond. 

Risk Profile 
Both instruments are backed by the full faith and credit of the Federal Government, making default risk effectively negligible for both — this is precisely why they’re treated as the benchmark “risk-free” rate in Nigeria’s financial markets. The real risk to consider isn’t default — it’s interest rate risk and inflation risk. Bonds, given their longer duration, carry more interest rate risk: if rates rise after you’ve locked in a fixed coupon, your bond’s market value falls (though your fixed income stream is unaffected if you hold to maturity). T-Bills, maturing far sooner, expose you to less of this risk, but more frequently to the need to reinvest at whatever rate is available when each tenor ends. On inflation: with Nigeria’s inflation rate still elevated, nominal double-digit yields on both instruments may not always translate to a meaningfully positive real return. This matters more for long-dated bonds, where you are locking in today’s nominal rate for years, than for T-Bills, where you get to reprice more frequently. 

Tax Treatment: The Detail Most Investors Miss 
This is the single biggest shift in the comparison as at today, and it changes the practical math significantly. Under the Nigeria Tax Act 2025 and subsequent FIRS directives, interest income from Treasury Bills is now subject to a 10% withholding tax, deducted at source by the paying agent. Meanwhile, interest income from Federal Government bonds remains tax-exempt. 
This means the gross yield gap between T-Bills and bonds is partly compensated by this tax difference. A T-Bill yielding 17% gross delivers 15.3% earnings after the 10% withholding tax, while a FGN Bond yielding 15% delivers the full 15% with nothing deducted. Depending on prevailing rates at the time, this can make bonds the more attractive after-tax option even when their headline rate is lower on paper. 

 This is exactly the kind of detail that is easy to miss if you are comparing headline rates alone — and exactly where having an investment expert model the after-tax outcome for your specific numbers pays for itself. 

Minimum Investment and Access 
Both instruments are more accessible than many investors assume. T-Bills can be accessed in the primary and secondary market through banks, licensed stockbrokers, and asset managers like us – Mainstreet Capital FGN Savings Bonds are deliberately structured for retail accessibility, with low entry points designed to bring everyday investors into the bond market, while standard FGN Bonds typically require larger initial investment amounts in line with institutional norms. 

So, Which Should You Choose? 
In practice, the better question is not “which is better?” it is “what is my investment goal and within what timeline?” 

• Choose T-Bills if you need short-term liquidity, you are investing money for a goal within the next year, or you want the flexibility to reprice(resell) your returns every few months as rates shift. 

• Choose FGN Bonds if you are investing for a multi-year goal, you want predictable periodic income, or the after-tax math (especially post-2026 tax changes) meaningfully favors your tax bracket. 

• Choose both if you’re building an actual portfolio rather than picking a single instrument — which is what most sophisticated, fixed income investors in Nigeria end up doing, laddering across tenors and instrument types to balance liquidity, income, and after-tax returns. 

 The honest answer for most investors is that this is not a one-time decision — it is an ongoing investment decision question that shifts as rates move, as your goals change, and as tax rules evolve. Getting it right consistently requires watching auction results, understanding where we are in the rate cycle, and knowing how to structure the after-tax outcome — which is a lot to track alongside everything else you are doing. 

 This is precisely the kind of structuring conversation our Treasury Management and Asset Management teams have with clients regularly. Whether you are trying to figure out the right T-Bill tenor for near-term liquidity, build a bond ladder for long-term income, or simply want someone to run the after-tax numbers before you commit, Mainstreet Capital’s fixed income trading and advisory desk can help you build a portfolio structured around your actual goals — not just whichever instrument happens to have the highest headline rate this week. 

 Rates and tax treatment referenced in this article reflect market conditions as of mid-2026 and are subject to change. Speak with an advisor before making investment decisions based on current rates.