How Annualized Yield Works Within Treasury Accounts
Business owners spend a lot of time learning how to most efficiently use their money. What they're doing when that money isn't actively being spent matters just as much. Some companies keep a significant portion of their operating cash sitting in a checking account earning little to nothing. Keeping that same cash in a treasury-backed account can bring meaningful returns without any extra effort.
Understanding annualized yield is the starting point for making better decisions about where to put your cash. It lets you compare accounts, investment vehicles, and financial products that express their returns in different ways. The size of a stated rate doesn't always equate to the returns you'll actually see, which is why it helps to know how it works under the hood.
This article explains what annualized yield is, how it differs from simple interest rates, how it's calculated, and how treasury yields are determined. We'll also take a look at Slash, a business banking platform offering a treasury account that earns up to 3.76% annualized yield through money market funds managed by BlackRock and Morgan Stanley.¹,⁶ Treasury sits in the same dashboard as your checking account, corporate cards, and financial tools with same-day to next-day liquidity so you can put idle cash to work without isolating it from the rest of your finances.
The standard in finance
Slash goes above with better controls, better rewards, and better support for your business.
Treasury Term Glossary
When it comes to discussing treasury accounts and yield rates, the terminology can be a little dense. Here’s a quick glossary of terms you should know before we begin:
- Treasury bills (T-bills): Short-term, low-risk debt securities issued by the U.S. government to fund federal spending, with maturities ranging from a few days to 52 weeks.
- Compounding rates: Interest calculated on both the initial principal and the accumulated interest from previous periods. Unlike simple interest, which is based only on the original amount, a compound rate allows your money to grow exponentially because you are "earning interest on interest".
- Debt securities: Financial assets that represent a loan made by an investor to a borrowing entity, such as a corporation or government.
- Bond markets: Financial marketplaces where investors buy and sell debt securities and T-bills issued by governments, municipalities, and corporations.
- Money market fund: A type of pooled investment fund that holds securities such as T-bills and commercial paper. Money market funds often provide higher yields than deposit accounts while remaining highly liquid.
What Is Annualized Yield?
Annualized yield differs from a simple interest rate. Interest rates tell you how much a deposit earns per period, but that period might be a week, a month, a quarter, or a year. Annualized yield standardizes the comparison by converting any given rate to its annual equivalent, accounting for the effects of compounding along the way.
For example, if a bank pays interest monthly on a deposit at a stated annual rate of 3.6%, each monthly payment is 0.3% of the principal. When the first month's interest gets added to the principal before the second month's interest is calculated, the effective annualized yield ends up slightly higher than 3.6%, closer to 3.66%. More frequent compounding amplifies this effect.
In the world of treasury, annualized yield is most often used to describe returns from short-duration instruments like T-bills. A 30-day T-bill might offer a yield of roughly 0.31% over its 30-day term. That sounds modest, but annualizing the rate (0.31% × 365/30) brings it to roughly 3.77%. The two figures describe the same investment, but annualized yield makes the comparison to other accounts meaningful.
For businesses managing operating capital, the yield on cash balances is a line item that finance teams often overlook. A business holding $500,000 in average operating balances earning 0.5% annually generates $2,500 in interest per year. The same $500,000 in an account earning 3.77% generates approximately $18,850.
How Annualized Yield Is Calculated
You don't need to do the math yourself to use annualized yield, but it helps to know what's happening behind the scenes. There are two ways to convert a periodic rate into an annual one:
When a rate compounds (meaning interest earns interest), the calculation accounts for that compounding effect. A 0.31% monthly rate doesn't simply multiply out to 3.72% (0.31% × 12) annually. Because each month's interest gets added to the principal before the next month's interest is calculated, the effective annualized yield ends up slightly higher, closer to 3.79%.
When a rate doesn't compound, the math is more direct. A 90-day T-bill yielding 0.92% over its full term annualizes to about 3.73% (0.92% × 365 ÷ 90). The bill pays out once at maturity, so there's no compounding effect to factor in.
A few things move the final number:
- Compounding frequency. Daily compounding produces a higher effective yield than monthly at the same stated rate. Most modern treasury and money market products compound daily.
- Investment horizon. Annualizing a yield from a very short holding period can produce numbers that look more volatile than they really are.
- Fees and expenses. Management fees, account fees, and expense ratios all reduce the yield you actually see.
If you want to run quick comparisons without doing the math, the U.S. Treasury's TreasuryDirect website publishes current yield data, and tools like Bankrate and the Federal Reserve's H.15 release show current and historical rates across maturities.
The Role of Compounding in Annualized Yield
Compounding frequency is the reason that two accounts with the same stated annual rate can produce different effective returns. At a stated rate of 3.60%, daily compounding produces an annualized yield of approximately 3.665% while monthly compounding produces approximately 3.660%. The difference looks small, but for companies with large treasury balances, it adds up.
A business holding $750,000 in an account with a 3.60% stated rate earns:
- With annual compounding: $27,000
- With monthly compounding: $27,453
- With daily compounding: $27,488
The difference between annual and monthly compounding on this balance is roughly $450, and daily compounding adds another $35 or so on top. The gap between annual and any more frequent compounding schedule is what really matters, which is why most modern treasury and money market products compound daily or monthly.
How Treasury Account Interest Rates Are Determined
In America, a few factors go into treasury account rates, some more intentional than others:
The Federal Reserve's Role
Treasury yields begin with the Federal Reserve. The Fed's Federal Open Market Committee (FOMC) sets the federal funds rate, which is the target range for overnight borrowing between banks. This rate anchors the short end of the yield curve. Because T-bills and overnight bank lending compete for the same short-term, low-risk capital, T-bill yields tend to trade closely to the federal funds rate.
As the Fed raises and cuts rates, short-term Treasury yields rise and fall in tandem. The federal funds rate is adjusted at eight scheduled FOMC meetings per year, along with guidance about expected future rates.
Market Demand and Economic Factors
Beyond the Fed's direct influence, Treasury yields are set by supply and demand in the bond market. The federal government issues Treasuries to fund deficit spending, then buyers purchase them based on their expected return relative to other options. These buyers include banks, institutional investors, foreign governments, and money market funds. High demand for Treasuries raises prices and lowers yield, while low demand means yields must rise to attract buyers.
Inflation expectations also matter. Because a bond's coupon is fixed in nominal terms, rising inflation hurts its real return. To compensate, investors often demand higher yields. This is why inflation data releases (CPI, PCE) frequently move Treasury yields.
How Banks Set Rates for Business Treasury Accounts
Banks and fintech platforms that offer treasury-backed accounts typically invest deposits in short-duration Treasury securities or government money market funds, then pass most of the yield through to account holders after retaining a small spread for operational costs. The rate businesses see is closely tied to the current T-bill yield environment, with the platform's spread determining how much of that yield is passed through. Slash Treasury, for example, invests in money market funds managed by BlackRock and Morgan Stanley.
The standard in finance
Slash goes above with better controls, better rewards, and better support for your business.
Types of Treasury Investments and Their Yields
When you put money into a treasury account or a Treasury-backed money market fund, the platform invests it across some combination of the instruments below. Each has a different maturity, yield profile, and role in how the underlying portfolio generates returns. Understanding what's in the mix helps clarify where your yield comes from:
- Treasury bills (T-bills): Short-duration government debt maturing in 4 to 52 weeks. Issued at a discount and paying no coupon, with the yield coming from the gap between purchase price and face value. The most liquid Treasury instrument and the standard for operating cash.
- Treasury notes: Maturities of 2 to 10 years with semi-annual coupon payments. Yields are typically modestly above T-bills, reflecting the longer term risk.
- Treasury bonds: Maturities of 20 or 30 years. Higher yields than short-duration instruments, but with mark-to-market risk if rates change. Not appropriate for operating cash.
- Treasury-backed money market funds: Pooled funds holding short-duration government securities, offering daily liquidity. Yields track the 3-month T-bill rate minus a small expense ratio.
- Treasury accounts through banking platforms: Combine the yield of short-duration Treasuries with the simplicity of a bank account. The platform handles the investment side, so businesses don't manage T-bill purchases directly.
Maximizing Annualized Yield for Your Business
Choosing a high-yield account is the first step, but a few habits go a long way toward getting more out of your cash. The biggest wins usually come from being deliberate about where balances sit, how often you revisit your setup, and what you're actually netting after fees. A small amount of regular attention can maximize what your idle cash earns over a year:
- Segment cash by when you'll need it: Keep about 30 days of expenses in checking, one to six months in a treasury account, and longer-term reserves in higher-duration instruments if you're willing to trade some liquidity for the potential of a higher yield.
- Set a target operating balance and sweep the rest: Calculate your monthly burn, multiply by 2 or 3 for buffer, and treat that as your checking target. Balances above that target may be candidates for a yield-bearing account.
- Reinvest the yield: Interest credited to your account can compound back into the balance rather than getting swept out. Most modern treasury platforms do this by default, but it's worth confirming with your provider.
- Review quarterly: Federal Reserve policy and market rates shift more often than most businesses revisit their cash setup. A short check each quarter helps you catch gaps before they cost you.
- Don't overcomplicate it: Beyond a point, chasing extra basis points across multiple providers can cost you more in operational overhead than you earn. One good integrated account can work better than using several average ones.
Earn Annualized Yield on Your Operating Cash with Slash
Slash Treasury offers an annualized yield of up to 3.77% on operating balances, generated through money market funds managed by BlackRock and Morgan Stanley. The treasury account lives directly within the Slash platform, alongside your checking account, corporate cards, expense tracking, and accounting integrations, so you don't have to isolate a portion of your money from the rest of your finances.
For businesses that have been keeping cash in a low- or zero-yield operating account, the difference can be significant. At the top current Slash Treasury rate, $100,000 in average operating balance would generate roughly $3,770 over a year if the rate held steady, compared to a fraction of that at many traditional business checking accounts. Actual returns will vary as market rates change. There's no separate investment account or manual T-bill purchases required to put idle cash to work.
Withdrawing money from your treasury account typically takes under 24 hours, subject to market cutoff windows. From there, you can send it across a wide range of payment rails, including card spend, global ACH, international wire transfers to over 180 countries via SWIFT, and real-time domestic payments through RTP and FedNow. With built-in on/off ramps, Slash also supports stablecoin transfers.⁴
Other Slash features include:
- Slash Visa® Platinum Card: Set customizable spending controls and issue unlimited virtual cards for team expenses, vendor payments, and subscriptions. Earn up to 2% cashback on business purchases.
- AI-powered finance: Twin, Slash's built-in AI agent, can be prompted with natural language to complete complex tasks. Users can ask it to create cards, pay invoices, review cash flow, and more.
- Accounting & ERP integrations: Sync transaction data with QuickBooks Online, Xero, NetSuite, or Sage Intacct to streamline reconciliation, reporting, and month-end close.
- Working capital financing: Access short-term financing with 30-, 60-, or 90-day repayment terms to bridge cash flow gaps.⁵
- Expense management: Submit, review, and approve reimbursements directly inside the Slash dashboard. Connect your bank account, upload your receipt, and let Slash capture the details.
Apply in less than 10 minutes today
Join the 10,000+ businesses already using Slash.
Frequently Asked Questions
How often is annualized yield paid out?
Interest payments depend on the account or instrument structure. Treasury-backed money market accounts typically accrue interest daily and credit it monthly, while direct T-bill purchases return your money at full maturity.
Treasury Management for Startups: A Complete Guide to Cash Flow, Liquidity & Risk
What's the minimum investment for treasury accounts?
Minimums vary by account type. Direct T-bill purchases through TreasuryDirect require a minimum of $100, while government money market funds often have minimums of $1,000–$10,000 for institutional classes. Slash Treasury, on the other hand, has no minimum balance requirement.
Treasury Account vs Savings Account: What's the Difference?
Are treasury yields guaranteed?
Amount-wise, treasury yields aren’t guaranteed in advance; rates change based on market conditions, and a new deposit made tomorrow earns the rate available tomorrow, not the rate available today.
Read more from us
