Treasury bills are short-term government securities that the Bank of Tanzania (BoT) sells on behalf of the government. They are one of the safest ways to earn a return on spare cash for a few months to a year. This guide explains how BoT treasury bill rates work, recent results and how to invest.
What treasury bills are
A treasury bill (T-bill) is a loan to the government. You buy it at a discount, for example paying about TZS 94 for every TZS 100 of face value, and receive the full face value when it matures. The difference is your return. The BoT offers bills with four maturities: 35, 91, 182 and 364 days.
Recent Bank of Tanzania treasury bill rates
T-bills are sold at auctions, usually every two weeks. The BoT treasury bill results page shows the outcome of each one. At auction No. 1208, held on 7 October 2026, the weighted average yields were:
- 35 days: 3.36%
- 91 days: 3.49%
- 182 days: 5.63%
- 364 days: 6.28%
Yields change at every auction with demand and with the BoT’s Central Bank Rate (6.25% in late 2026), so check the latest results before you bid. Longer bills usually pay more. The 364-day bill is often heavily bid, while short bills can be undersubscribed.
How to invest in treasury bills
- Open a Central Depository System (CDS) account for government securities, through the BoT or a commercial bank or licensed broker that acts as an agent.
- Check the auction calendar and the “call for tender” on the BoT website.
- Submit a competitive bid (you state the price) or a non-competitive bid (you accept the average price) before the deadline.
- If your bid succeeds, pay by the settlement date. At maturity, the face value is paid into your account.
The BoT website also has a treasury bills investment calculator to estimate your return.
Treasury bills vs bank deposits
T-bills are backed by the government, while bank deposits are insured by the Deposit Insurance Board only up to TZS 7.5 million per depositor. T-bill yields can be higher or lower than fixed deposit rates, so compare both. Read our guides to bank interest rates in Tanzania and fixed deposit rates. For the bigger picture, see our article on Bank of Tanzania financial markets, and for long-term investing, our guide to stock brokers in Tanzania.
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