A high-yield savings account is a deposit account whose interest may compound monthly, depending on the bank. Some banks calculate interest daily and credit it monthly. Others use quarterly or annual schedules. APY accounts for the effect of compounding over 365 days, making it more useful for comparing accounts than the stated interest rate alone.
Federal rules do not require banks to use a specific compounding frequency. Banks must disclose how often interest is compounded and credited in the account terms.
How High-Yield Savings Account Compounding Works
Compound interest is interest earned on your original deposit and on interest already added to the account. Once interest becomes part of the balance, later interest calculations may include that additional amount.
A high-yield savings account may use one of these methods:
| Account method | What happens |
|---|---|
| Monthly compounding | Interest is added to the balance once per month, so later calculations can include it. |
| Daily compounding, monthly crediting | Interest is calculated or accrued daily but posted to the account monthly. |
| Quarterly or annual compounding | Interest is added less often, according to the account agreement. |
"High-yield" describes the account's relatively competitive interest rate or APY. It does not guarantee a particular compounding schedule.
Does Monthly Crediting Mean Monthly Compounding?
No, not by itself. Monthly crediting tells you when the bank posts interest to your account. Monthly compounding tells you how often previously earned interest is included when calculating future interest.
A bank can calculate or compound interest daily and credit it monthly. The Consumer Financial Protection Bureau recognizes this distinction in its regulations.
Capital One, for example, states that its 360 Performance Savings account compounds and credits interest monthly.
Why APY Matters More Than Compounding Frequency
APY, or annual percentage yield, is usually the better number to compare between high-yield savings accounts. It reflects both the interest rate and the effect of compounding over a 365-day period.
For example, assume a constant 4% interest rate and a $10,000 balance:
- Monthly compounding would produce approximately $407.42 in interest over one year.
- Daily compounding would produce approximately $408.08.
- The difference would be about $0.67 before taxes.
The interest rate, balance, time invested and account fees usually matter more than the small difference between daily and monthly compounding.
How to Check Your Account's Compounding Schedule
Read the bank's account agreement and disclosures. Look for:
- Compounding frequency: Whether interest compounds daily, monthly, quarterly or annually.
- Crediting frequency: When the bank posts interest to your balance.
- Interest calculation method: Whether the bank uses your daily balance or average daily balance.
- Variable APY disclosure: Whether the bank can change the rate.
- Minimum balance or fee requirements: Conditions that could reduce your earnings.
Bottom Line
If two accounts have similar APYs, compare their fees, minimum balance requirements and access to funds. Use the account agreement to confirm whether each account compounds and credits interest monthly.