Treasury Bill Rates Kenya September 2026: What the Latest CBK Rates Mean

Kenya’s latest Treasury Bill reference rates are clustered tightly around 9%. The Central Bank of Kenya currently shows the previous average interest rate at 8.7687% for the 91-day bill, 8.9331% for the 182-day bill and 9.0737% for the 364-day bill.

The next auction is dated 10 September 2026, with a value date of 14 September 2026. Those percentages are useful reference points, but they are not interchangeable with the return from a bank account, money market fund or even another T-Bill tenor. The time your money is committed matters.

Latest Treasury Bill rates in Kenya

*The gap is a simple comparison of annual quoted rates with headline annual inflation. It is not an estimate of your actual real return.

The spread between the shortest and longest T-Bill is only about 0.305 percentage points. That makes the maturity period an important part of the comparison: the 364-day bill carries the highest quoted rate, but it also has the longest maturity.

What the 91-day, 182-day and 364-day labels mean

CBK describes Treasury Bills as short-term government debt sold at a discount and repaid at face value at maturity. The three standard maturities are 91, 182 and 364 days, and they are auctioned weekly.

A 91-day bill therefore gives you a much earlier maturity date than a 364-day bill. The quoted rate is annualised, so you should not read an 8.7687% 91-day rate as meaning a 91-day investment automatically grows by 8.7687%. The purchase price and maturity value determine the actual cash outcome for the holding period.

For a step-by-step explanation of the auction and discount structure, read How Treasury Bills work in Kenya.

How current T-Bill rates compare with inflation

Kenya’s annual consumer inflation was 6.6% in August 2026, according to the Kenya National Bureau of Statistics. Each of the three current T-Bill reference rates sits above that headline figure.

That does not mean the difference is a guaranteed “real return.” Inflation is measured over a year, while a 91-day or 182-day bill matures sooner. Inflation can also change during your holding period, and taxes or other applicable costs affect what you ultimately keep.

Still, putting the figures side by side is useful because it shows the current relationship between the government’s short-term borrowing rates and the latest change in consumer prices. Amka’s inflation, deposit and lending rates explainer adds bank deposits, savings rates and lending rates to the same picture.

The next CBK Treasury Bill auction is 10 September

CBK currently lists issue 2699/091 for the 91-day bill, 2673/182 for the 182-day bill and 2628/364 for the 364-day bill. All three have an auction date of 10 September 2026 and a value date of 14 September 2026.

The important word on the CBK page is previous: 8.7687%, 8.9331% and 9.0737% are the previous average interest rates shown ahead of the next auction. They are not a promise that the next accepted averages will be identical.

What to compare beyond the headline percentage

First, compare the maturity date with when you may need the money. A slightly higher annualised rate may be less useful if the tenor does not fit your liquidity needs.

Second, compare unlike products carefully. A money market fund typically has a changing published yield and different access terms, while a bank fixed deposit has its own rate, term and withdrawal rules. A Treasury Bill is a government security sold at auction. The percentages may look similar, but the products work differently.

Third, always verify the live source. Treasury Bill rates can move from one weekly auction to the next, which is why Amka keeps a dedicated Treasury Bill rate board alongside the explanatory articles.

Sources

• Central Bank of Kenya — Treasury Bills and current auction information ↗
• Central Bank of Kenya — How Treasury Bills work ↗
• KNBS — Consumer Price Indices and Inflation Rates, August 2026 ↗