How Often Do HYSAs Compound? Daily Interest and Credit Dates

High-yield savings accounts almost always compound interest daily, then credit the accumulated earnings to your balance once a month at the close of the statement cycle. So the bank is doing the math every day, but the money only shows up in your account on one day per month. That two-step rhythm — daily calculation, monthly payout — is the standard across most online HYSAs, and knowing the difference between the two steps changes how you time deposits, withdrawals, and account closures.

How Daily Compounding Works

Daily compounding means the bank divides your annual interest rate by 365 to produce a tiny daily rate, then applies that rate to your end-of-day balance. If your account carries a 4.50% annual rate, the daily rate works out to roughly 0.01233%. Monday’s interest becomes part of the balance that earns Tuesday’s interest, and so on. Over a full year, this cycle produces slightly more than the nominal rate would suggest, because each day’s earnings start working immediately.

Leap years get handled one of two ways. Some banks divide the annual rate by 366 instead of 365; others keep the 365 divisor and apply it for one extra day.¹ Both are allowed, and the dollar difference is negligible.

Compounding Is Not the Same as Crediting

Compounding is the daily calculation on the bank’s internal ledger. Crediting is the moment those accumulated earnings actually post to the balance you can see and spend. For most high-yield savings accounts, crediting happens once a month at the close of your statement cycle.

Between crediting dates, your daily interest exists only as an internal tally. The bank tracks it, and it feeds into the next day’s compounding, but it has not officially posted yet. At the end of the month, all those daily amounts land in your account as a single deposit. That is why you see one interest payment per month rather than thirty small ones.

What Happens If You Close or Withdraw Before the Credit Date

This gap between compounding and crediting can cost you money if you move at the wrong time.

If you close the account partway through the month, the interest that has compounded since the last crediting date may not follow you out. Federal rules allow the bank to keep that accrued interest, as long as it disclosed the policy when you opened the account.² Many banks do pay it out on closure anyway, but they are not required to. Before closing a high-yield savings account, check the disclosure. If it says interest is forfeited on early closure, waiting until just after the monthly credit posts can save you several weeks of earnings.

The rule is friendlier when you take money out but keep the account open. A bank cannot withhold interest that has already accrued on funds you withdraw, as long as the account stays open.¹ That accrued interest still posts on the next crediting date, even though the principal that generated it is gone.

What Daily Compounding Is Actually Worth

The Annual Percentage Yield, or APY, is the number that captures the real effect of compounding over a full year. The nominal interest rate is the base figure the bank plugs into its daily calculation; the APY shows what you actually earn once compounding is layered in. A 4.50% nominal rate with daily compounding produces an APY of about 4.60%.

Federal law requires every bank and credit union to calculate and disclose the APY using a standardized formula, so accounts can be compared on equal footing regardless of how often each one compounds.³ Regulation DD also bars a bank from advertising any rate more prominently than the APY, keeping the focus on the figure that reflects your real earnings.²

The practical difference between daily and monthly compounding at the same nominal rate is real but modest. On a $10,000 deposit at a 4.50% nominal rate, daily compounding earns roughly $460.25 over a year, while monthly compounding earns about $459.40. At $100,000, the gap widens to around $8.50 per year. The benefit grows with balance and rate, but because APY already bakes it in, the number you see advertised is the number you earn.

When New Deposits Start Compounding

Under the Expedited Funds Availability Act, a bank must begin accruing interest on your deposit no later than the business day it receives provisional credit for the funds.⁴ For an electronic transfer, that is usually the day the money arrives. For a check deposit, accrual starts once the bank gets provisional credit, typically one or two business days later, not when the check fully clears. Interest keeps accruing until the day you withdraw.

Your account’s Truth in Savings disclosure must spell out exactly when interest begins on noncash deposits.² If you regularly deposit paper checks, that timing detail is worth confirming.

Finding Your Account’s Compounding and Crediting Terms

Every bank and credit union has to provide a Truth in Savings disclosure before you open an account.⁵ It states the compounding frequency, the crediting schedule, any minimum balance needed to earn the advertised APY, and whether accrued interest is forfeited on early closure. Online banks usually post it as a PDF linked from the product page, labeled “Truth in Savings,” “Account Agreement,” or “Deposit Account Disclosures.”

Look for the section describing how interest is calculated and when it is credited. Regulation DD requires the disclosure to state the minimum balance needed to earn the APY and to explain how that balance is figured, whether by daily balance, average daily balance, or another method.² Reading those lines before opening the account prevents surprises later about balance thresholds or when the monthly credit lands.

1
Consumer Financial Protection Bureau. Comment for 1030.7 – Payment of Interest
2
eCFR. 12 CFR Part 1030 – Truth in Savings (Regulation DD)
3
Consumer Financial Protection Bureau. Appendix A to Part 1030 – Annual Percentage Yield Calculation
4
Office of the Law Revision Counsel. 12 U.S. Code 4005 – Payment of Interest
5
National Credit Union Administration. Truth in Savings Act (NCUA Rules and Regulations Part 707)