Card Terminal Real Monthly Fixed Costs: Why Transaction Fees Alone Are Not Enough — 2025 Merchant Cost Structure Analysis

The reality for merchants is that payment costs do not automatically decrease even as sales increase. According to 2025 card approval data released by the Credit Finance Association, domestic card approval amounts reached 1,266 trillion won with 4.7% year-over-year growth, but the conditions experienced by merchants remain largely unchanged. In particular, as the healthcare industry records the highest card approval growth rate at 7.8% across all sectors, everyone from large general hospitals to small clinics faces the same structural problem: it is difficult to improve actual net profit by simply lowering the transaction fee rate.

Jaiwoo Shim, CEO of ThKL Link, emphasizes that "payment costs must be calculated as a total including not just transaction fees but also terminal rental fees, monthly fixed management fees, communication costs, and maintenance fees to determine whether current conditions are appropriate." In reality, merchants often incur greater losses from hidden fixed costs while comparing fees based solely on settlement statements.

Looking at data from the Bank of Korea and the Credit Finance Association, the daily average PG (Payment Gateway) service usage amount in 2025 reached 1,554.2 billion won, a 9.2% increase from the previous year. In particular, the daily average number of transactions reached 33.64 million, representing an 11.8% increase, with transaction volume growing much faster.

However, why doesn't the fruit of this growth return entirely to merchants? It is because fixed cost structures accumulate regardless of sales increases.

•Transaction fees are proportional to sales, but terminal rental fees and monthly management fees occur regardless of sales

•Whether monthly sales are 5 million won or 50 million won, monthly fixed costs remain at nearly the same level

•When settlement is delayed, cash flow worsens, causing additional financial costs to arise

According to ThKL Link's analysis of recent three-month settlement statements, the cost items merchants overlook are as follows:

Card Terminal Rental Fee: 30,000~80,000 won per month. Total of 720,000~1,920,000 won for 2-year contract

- Some terminals are advertised as "free," but early termination fees may be charged depending on contract conditions - Older terminals may incur separate repair or replacement charges

Monthly Management Fee (Maintenance Fee): 10,000~30,000 won per month

- Outwardly claimed as "cost only when problems occur," but may be charged as regular inspection fees or software update costs

Communication Fee (LTE·Wired): 20,000~50,000 won per month

- For wireless terminals, data charges are billed in a separate account - When withdrawing from bundled rate plans, unit pricing may increase

Early Termination Penalty: 100,000~500,000 won per terminal

- Occurs when changing terminals during contract period - Acts as unexpected cost when relocating business or closing

Cancellation·Refund Fee: 20,000~100,000 won per month (varies by transaction volume)

- In industries with frequent cancellations and refunds (healthcare, beauty, food service), may be processed separately from transaction fees

The method recommended by CEO Shim Jaiwoo for calculating actual monthly costs for merchants is as follows:

Extract Transaction Fees from Settlement Statement: Record only the "transaction fee" item from recent three-month settlement statements

- Confirm monthly variations (peak vs. off-peak seasons) - Separately calculate cancellation and refund fees

Organize Fixed Costs from Contract: Review card terminal contracts and communication fee invoices

- List monthly rental fees, management fees, communication fees, and additional service charges by item - Confirm additional costs within contract period (equipment damage fees, maintenance fees)

Monthly Total Cost ÷ Monthly Card Sales × 100 = Actual Cost Rate (%)

- Example: Monthly card sales 20 million won, transaction fee 320,000 won + fixed cost 150,000 won = total 470,000 won - Actual cost rate = 470,000 won ÷ 20 million won × 100 = 2.35% - Difference between official transaction fee rate (2%) and actual cost rate (2.35%) = 0.35% = hidden cost of 70,000 won per month

According to the investment proposal presented by ThKL Link, the payment revenue structure itself is changing. While the global payment industry reached 2.5 trillion dollars in 2024, revenue sources are shifting from the past card fee-focused revenue model to bank transfers, digital wallets, and AI-based value-added services.

The same trend is occurring domestically. The reason the healthcare industry's card approval growth rate reached 7.8% in 2025, the highest across all sectors, means that high-value transactions in non-covered medical procedures, cosmetic surgery, and skin care are increasing, which in turn signifies diversification of PG services centered on medical institutions and high-value merchants.

•Increased Same-Day Settlement Demand: More merchants are switching from existing D+1 settlement to same-day settlement

- Same-day settlement carries transaction fees 0.1~0.3% higher, but improved cash flow can offset this through financial cost savings

•AI CRM-Based Value-Added Services: Expansion from simple payment processing to customer data and repeat visit marketing

- In medical institutions, solutions integrating patient repeat visit marketing are expected to become standardized by 2028

•Limited "Free Terminal" for Small Merchants: Possibility of reduced free support due to high technology maintenance costs

Comparing the 2025 PG daily average usage of 1,554.2 billion won with 33.64 million transactions means the average transaction amount per transaction is decreasing. This signifies that as small-value transactions increase, the relative burden of offline terminal management costs is growing.

The cost gap between offline PG (card terminal) and online PG is:

| Cost Item | Offline PG | Online PG | Difference |
|----------|----------|----------|--------|
| Transaction Fee Rate | 1.5~3.5% | 2.0~3.0% | Offline has higher risk with greater volatility |
| Terminal·Equipment Cost | 20,000~80,000 won/month | None | Offline essential, online software cost only |
| Fixed Management Fee | 20,000~50,000 won/month | 0~10,000 won/month | Offline equipment maintenance cost mandatory |
| Settlement Cycle | D+1 ~ D+3 | D+0 ~ D+1 | Online faster, advantageous cash flow |
| Monthly Total Fixed Cost | 100,000~200,000 won | 20,000~50,000 won | Offline approximately 3x higher |

Field Analysis: For a small clinic with 10 million won in monthly card sales:

•Offline PG: Transaction fee 200,000 won + fixed cost 150,000 won = Total 350,000 won (3.5%)

•Online PG (with mobile payment): Transaction fee 220,000 won + fixed cost 20,000 won = Total 240,000 won (2.4%)

•Offline-Online Cost Gap: 110,000 won per month (1,320,000 won annually)

One of the core strategies ThKL Link proposes is "settlement cycle selection system." The difference between typical D+1 (next-day settlement) and same-day settlement appears simple but has significant impact on merchant cash flow management.

Cash Effect Calculation by Settlement Cycle:

•Assume a merchant with daily card sales of 5 million won

•D+1 Settlement: January 1st transaction → January 2nd deposit (1-day delay)

•Same-Day Settlement: January 1st transaction → January 1st deposit (immediate deposit)

Over the entire month, same-day settlement creates an effect of securing funds 1.5 days earlier on average = experiencing 7.5 million won in advance deposit for the month. Managed at annual interest rates of 3~5%, this enables creation of 20,000~30,000 won in additional monthly revenue.

•Peak Season Cash Flow Improvement: Healthcare, beauty, and food service industries have significant sales volatility in certain periods, improving operational stability with same-day settlement

•Advantageous in Small-Value High-Volume Transaction Environment: The lower the transaction amount, the greater the cumulative impact of settlement delays

•Additional Cost is 0.1~0.3% Increase: If the same-day settlement fee increase is smaller than the cash flow improvement effect, net profit increases

Q1: How can I verify whether my transaction fee is really high?

A: Obtain recent three-month settlement statements, then divide the monthly total "transaction fee" item by that month's card sales. Generally, offline small merchants fall in the 1.5~2.5% range, while healthcare facilities and food service businesses fall in the 1.8~3.0% range. If it's 3.5% or higher, contract review is necessary. ThKL Link provides free diagnostic service, so comparison is possible through consultation (010-2397-5734).

Q2: Do I have to pay higher transaction fees to receive same-day settlement?

A: Same-day settlement typically carries 0.1~0.3% higher transaction fees. However, when cash flow improves, financial costs (loan interest, credit costs) decrease, so the actual burden may be small. If monthly card sales are 10 million won or higher and peak season operational stability is important, it is worth considering.

Q3: I frequently see advertisements for free card terminals—are they really free?

A: While superficially free, early termination fees of 100,000~500,000 won are charged if terminated during the contract period (typically 2~3 years). Additionally, maintenance fees and communication fees are often separate. You must verify detailed contract terms carefully and understand the actual monthly fixed cost structure before contracting.

Q4: Do I need to replace terminals if I change PG services?

A: Replacement is necessary in most cases. First confirm your previous PG contract to identify whether termination fees occur, and negotiate conditions such as "free equipment support + settlement cycle selection system" with the new PG. Using a PG agency like ThKL Link can reduce costs when changing contracts.

Q5: If I have many payment cancellations·refunds, do additional costs occur?

A: Some PGs charge refund fees separately. Industries with frequent cancellation and refund transactions, such as healthcare, beauty, and food service, must verify this item before contracting. ThKL Link's service proposal presents a method of explicitly managing this item.

With the 2025 domestic payment market growing 4.7% annually and the healthcare industry growing 7.8%, for merchants to genuinely increase profits requires redesigning the entire payment cost structure rather than simply reducing transaction fees. Cost improvements of 1.2~2 million won annually are possible simply by reducing the 100,000~200,000 won in hidden monthly fixed costs, shortening the settlement cycle, and renegotiating contract terms.

ThKL Link provides a medical fintech platform that manages payment environment diagnosis, installation, settlement, and maintenance from start to finish in central Seoul. As CEO Shim emphasizes, under the philosophy that "payment is not the final stage of a transaction but the starting point reconnecting customers and businesses," the goal is overall cash flow optimization rather than simple fee reduction.

If you want to verify whether your business's payment costs are appropriate, prepare recent three-month settlement statements and contracts, then request consultation. Consultation is available at 010-2397-5734 or jaiwshim@gmail.com.

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