Credit card interest rates- How to calculate and limit overdue interest

Credit card interest is a fee incurred during the use of the card. In reality, many customers only begin to realize this fee when their statement shows an increase, even without making any additional purchases. This is often due to incorrect payment methods, cash withdrawals, or late payments.

This article will help you understand what credit card interest is, when interest is charged, and how to effectively control your expenses when using your card.

1. What is credit card interest? When does credit card interest accrue?

Credit card interest is a fee charged by banks when cardholders use funds provided by the bank in advance but fail to repay the full amount or on time as stated in their statement.If paymentBy completing all transactions fully and on time as stipulated by the card-issuing bank, cardholders may not incur interest during the interest-free period applicable to each transaction.

In practice, credit card interest typically accrues in the following situations:

• Withdraw cash using a credit card: Interest is calculated immediately upon making a cash withdrawal at an ATM, with no interest-free period. This is a high-cost form of card usage due to both interest charges and cash withdrawal fees.
• Insufficient payment of outstanding balance at the end of the period: When the cardholder only pays the minimum amount stated on the statement, interest will be charged on the remaining balance, starting from the date of the transaction until it is fully repaid.
• Late payment compared to the due date: If the minimum payment is not made before the due date, the bank will apply late payment interest and charge additional late payment fees, causing the total financial obligation to increase rapidly.
• Installment payment options: For credit card installment payments, interest is calculated according to the installment agreement. For 0% interest installment programs, cardholders only pay the principal amount periodically as agreed.

Failing to pay off the remaining balance at the end of the billing cycle is the primary reason for credit card interest charges.

2. How is interest calculated on credit cards?

Depending on the type of transaction, credit card interest rates are calculated according to different principles. Understanding how they are calculated helps cardholders proactively control costs and avoid incurring unwanted interest charges.

2.1. Interest on cash withdrawals at ATMs

Withdrawing cash using a credit card is considered a high-cost form of short-term borrowing because it doesn't offer an interest-free period and incurs additional transaction fees.

How to calculate interest on cash withdrawals:

Key features to note:

• Interest is calculated from the date of withdrawal; there is no interest-free period.
• Cash withdrawal feesFees are determined according to the fee schedule of each bank and card type, usually calculated as a percentage of the withdrawal amount, with a minimum amount per transaction.
• Interest and fees are added directly to the card balance.

For example:The customer withdrew 10 million VND on May 15th, with an interest rate of 18% per year, and made full payment on May 30th (15 days).

• Interest: 10,000,000 * 18% / 365 * 15 ≈ 74,000 VND
• Withdrawal fee (4%): ≈ 400,000 VND

Therefore, the total amount to be reimbursed is approximately 10,474,000 VND.

2.2. Interest on non-full payment (revolving debt)

Revolving credit is incurred when a cardholder does not pay the full amount due according to their statement, but only pays the minimum amount.

Principles of interest calculation:

• Pay off 100% of the outstanding balance on time: No interest will be charged during the interest-free period.
• Pay only the minimum amount: Interest is calculated on the remaining balance, starting from the date of the initial transaction.

Here's how to calculate interest (for reference):

For example:

Total outstanding debt of 20 million VND from multiple shopping transactions. The cardholder pays a minimum of 5% (1 million VND), leaving a remaining balance of 19 million VND. With an interest rate of 25% per year for 30 days:

Interest ≈ 19,000,000 * 25% / 365 * 30 ≈ 388,000 VND, which will be added to the next statement.

2.3. Interest when buying on installment using a credit card.

Installment payments using a credit card allow you to break down your expenses into smaller payments over several periods. The applicable interest rate depends on the installment plan the cardholder has registered for.

How to calculate installment interest:

Currently, many banks are offering 0% interest installment programs through their partner organizations. In cases not covered by the 0% program, interest rates may apply as follows:

• Fixed monthly interest rate
• Declining interest rates
• One-time installment conversion fee (approximately 3-10%)

For example:If you buy goods worth 12 million VND and pay in installments over 12 months with an interest rate of 1.5% per month, the monthly payment would be approximately 1,180,000 VND (including principal and interest).

2.4. Interest on late (overdue) payments

If the cardholder fails to make payments on time according to the statement, the bank will apply late payment interest and penalties.

Common methods for calculating late payment interest today:

In addition, cardholders are also subject to late payment penalties, usually ranging from 4-6% of the outstanding balance, with a common minimum of VND 100,000 - 150,000 per statement period.

Some points require special attention:

• Overdue interest rates are applied according to the regulations of each bank and are usually higher than in-term interest rates.
• Interest is calculated continuously on the entire outstanding balance, including any applicable penalties.
• The longer the delay, the faster the total financial cost increases.

Understanding how credit card interest rates are calculated helps customers proactively control their expenses.

3. Ways to limit credit card interest charges

To use credit cards effectively and avoid falling into the "interest rate trap," cardholders should proactively implement the following solutions:

• Full Payment: It is preferable to pay 100% of the amount spent before the due date to take full advantage of the interest-free period (usually 45-55 days).
• Limit cash withdrawals: Only use in emergencies because withdrawal fees are around 4%, coupled with high interest rates, which can reach 20-40% per year.
• Take advantage of 0% installment payments: Choose to shop at partner banks to spread your spending out without incurring interest or conversion fees.
• Set up automatic payments: Setting up automatic debits from your payment account helps avoid missed deadlines and reduces penalties and late payment interest.
• Minimum payment required: If you cannot afford to pay the full amount, please pay at least 5%.outstanding debt to avoidRisk of having an unfavorable credit history recorded at the Vietnam National Credit Information Center (CIC).
• Monitoring spending via app: Track statements, payment schedules, and limits directly on your banking app for more proactive financial control.

Paying off your balance in full and on time helps limit the interest charges on your credit card.

4. Which bank offers the lowest credit card interest rate?

Currently, credit card interest rates in Vietnam typically range from 12% to 40% per year, depending on the bank and card type. Choosing a card with a low interest rate depends not only on the listed rate but also on several other factors:

• Card tiers: Premium cards (Platinum, Signature, Infinite) usually offer more favorable interest rates compared to standard cards.
• Banking groups: State-owned banks (Big4) or foreign banks typically maintain stable and lower interest rates than the general market average.
• Customer segment: VIP/Priority customers typically enjoy privileged fee schedules and interest rates.
• Phased promotional programs: Many banks offer preferential interest rates for new cardholders or installment transactions during the first year.

Southeast Asia Commercial Joint Stock Bank (SeABank) currently offers a diverse range of credit cards with fees and interest rates publicly disclosed for each product.  

>> See alsoLatest interest rates for SeABank personal credit cards.

SeABank is highly regarded for its transparent interest rates and many attractive promotional programs when using its cards.

Understanding how interest rates and penalty fees are calculated, and choosing the right credit card, will help customers use their cards safely, efficiently, and optimize their finances. If you need to apply for a card, compare interest rates, or require detailed advice tailored to your specific application, you can contact SeABank directly for prompt, accurate, and up-to-date support in accordance with the latest regulations.