Ultra-low-cost budget mobile plans priced below 1,000 won a month are emerging one after another, helping households cut telecom bills. Some products, however, are structured so that monthly fees rise to tens of thousands of won once the discount period ends. That has prompted calls for users to weigh the real burden of long-term use.

As of Oct. 23, major operators are rolling out steeply discounted plans for new subscribers and number-porting customers, with monthly fees of 10 won, 100 won and 990 won, the budget mobile industry said. Some products offer tens of gigabytes of data for less than 10,000 won a month.

Budget mobile services use a mobile virtual network operator, or MVNO, model that provides service by leasing networks from the three major mobile carriers. With no need to build their own networks and by cutting distribution and marketing costs, MVNOs offer relatively cheaper plans.

Satisfaction with fees among MVNO users was higher than among users of the three major mobile carriers. In a 2024 survey by the Korea Consumer Agency, MVNO users rated fee satisfaction at 3.91 out of 5, above 3.10 for users of the three major carriers. Satisfaction with plan selection was also higher for MVNOs at 3.82, compared with 3.53 for the three carriers.

The government also sees MVNOs as a key tool to boost competition in the telecom market and reduce household telecom bills. In an MVNO activation plan announced in July, the Ministry of Science and ICT said it would pursue a partial cut in 5G wholesale rates and expand reductions in spectrum usage fees for small and midsize MVNO operators.

At 10 won a month to 18,700 won: fees 'jump' after discounts end

Many ultra-low-cost MVNO plans are promotional products that apply discounted prices only for a set period. They offer discounts for as little as 6 months and as long as 24 months, before applying standard rates.

According to MVNO Hub run by the Korea Association of Information & Telecommunication, an A product offering 10GB of data and 200 minutes of voice calls for 10 won a month switches to 18,700 won a month after 7 months. A B product offering 4.5GB of data for 990 won a month also moves to 9,900 won a month after 12 months.

For plans with larger data allowances, the gap is bigger. A C product offering 11GB of data plus an extra 2GB daily for 4,500 won a month switches to 36,300 won a month after 7 months. The monthly difference before and after the discount ends exceeds 30,000 won. The total paid over the 7-month discount period is 31,500 won, but the monthly fee afterward exceeds that amount.

Some large-data plans apply a discounted price of less than 10,000 won a month but rise to 40,000 to 50,000 won a month after the promotion ends. The structure means that the higher the initial discount rate, the larger the gap with the post-discount fee. With the actual burden varying depending on the discount period and standard rate, the industry says it is difficult to judge whether a plan is cheap based only on the initial price.

Good for short-term use, but check how discount-end notices work and subscription conditions

Users who plan to keep the same plan long term should pay closer attention to the fee after the discount ends. That is because many products apply the standard rate without any separate application process once the discount period ends, even if the plan initially costs only a few thousand won a month. Users who are not used to changing plans or who miss the discount-end date may face higher-than-expected telecom bills.

To avoid that, it is advisable to review subscription conditions closely. An MVNO industry official said, "There are 'grasshopper' users who switch plans frequently, but they should instead watch out for discount clawbacks," adding, "You need to check the minimum subscription period." Some products listed on MVNO Hub have a minimum retention period of 93 days, including the activation date. If users cancel during that period, they must repay the amount of discounts they received.

Users should also check how they will be notified when discounts end. Even if they confirm the post-discount fee at sign-up, they may miss the change date months later. That has also led to calls for system design that makes it easy to check the discount-end date and the revised fee in advance.

The government is also working to boost MVNO competitiveness while strengthening user protection. The Ministry of Science and ICT held an industry meeting on Sept. 30 to discuss follow-up steps to the MVNO activation plan, including raising customer service standards and strengthening user protection.

An MVNO industry official said, "Ultra-low-cost promotions are beneficial in that consumers can use telecom services at cheaper prices than before," adding, "It is important to choose a plan by considering your usage period and data consumption."