Earn Interest Even for a One-Day Deposit: How to Get 200% Out of CMAs and Parking Accounts
Say your salary lands on the 25th and your card bill is debited on the 14th of the next month. For roughly three weeks in between, the money sitting in your account is 'sleeping money.' In a regular checking account with a rate around 0.1% per year, you effectively earn no interest. Put that same money in a CMA or a parking account, and interest accrues by the day. This article isn't recommending any specific product; it's a reference to help you understand the 'structure' of putting short-term spare cash to work, using numbers.
Why Does Interest Accrue 'Even for a One-Day Deposit'?
CMAs vs. Parking Accounts: What's the Difference?
- Parking account (bank): Covered by deposit protection (up to 50 million KRW per person, principal plus interest combined). Usually 'capped,' meaning the preferential rate applies only up to a certain amount, with the excess earning the base rate.
- CMA RP type (securities firm): Invested in repurchase-agreement bonds. Not covered by deposit protection, but classified as relatively stable since it's backed by high-grade bond collateral.
- CMA promissory-note type: Issued by comprehensive financial investment business operators above a certain capital threshold. Not covered by deposit protection.
- CMA MMF/MMW type: Linked to market rates. Not a fixed rate, so the yield shifts slightly each day depending on management performance.
Calculating the Actual Interest with Numbers
Does It Matter Even with Small Amounts?
The Trap of 'Preferential-Rate Caps' and 'Special Offers'
- Define the purpose: Set aside only money that 'might be needed soon'—like an emergency fund or short-term standby cash—for parking.
- Check protection status: If safety is your top priority, use a deposit-protected bank parking account and stay within the cap (50 million KRW).
- Check the rate structure: Calculate the rate actually applied to 'your amount and your period,' not the headline rate.
- Account for taxes: Remember that the pre-tax rate × 0.846 (after deducting 15.4%) is your real yield.
- Diversify: If you exceed 50 million KRW, splitting across banks to secure the deposit-protection cap for each is one approach.
Know About Taxes and Comprehensive Financial Income Taxation Too
The goal of short-term funds isn't 'earning a lot'—it's 'keeping them safe while making sure they don't drop to zero.'
Money You Should NOT Put in Parking
To sum up, CMAs and parking accounts are tools for 'briefly and safely putting money you'll soon spend to work.' Calculate the rate actually applied to your amount and period—not the advertised rate—and weigh both deposit protection and taxes (15.4%). The figures in this article are illustrative examples to aid understanding; actual rates and conditions vary by product and timing. Be sure to check each financial institution's product disclosure before opening an account. (This content is for informational reference purposes only and is not a recommendation to invest in any specific product.)