NTS chief says agency will calculate most favorable property tax for couples who jointly own one home

National Tax Service Commissioner Lim Gwang-hyeon announced Sunday that the NTS will, for the first time, calculate and notify married couples who jointly own a single home of the most favorable comprehensive real estate tax amount available to them — and will also identify and refund cases where such couples overpaid in the past.

Lim made the announcement on X, formerly Twitter, saying the agency had identified about 5,700 joint-ownership taxpayers who would benefit from applying for the special tax regime, as well as roughly 2,900 existing applicants who would be better off canceling it. He said the NTS would notify each group individually by mobile message or mail with their projected most favorable tax bill for the year.

"If you refer to the projected favorable tax amount you receive and submit an application or cancellation between Sept. 16 and Sept. 30, the most favorably calculated tax amount will automatically appear on your November regular tax notice," Lim said, and went on to say that taxpayers who miss that window can still file in the most advantageous way during the December comprehensive real estate tax filing period.

The NTS plans to analyze past applicants under the special regime, identify taxpayers who overpaid, notify them individually and proceed with refund procedures.

The comprehensive real estate tax was originally assessed on a household-combined basis, but the Constitutional Court ruled in 2008 that it must be levied on an individual basis.

That change created a situation where married couples who jointly own a single home could end up paying more than those who hold a home under a single name, prompting the introduction in 2021 of a special regime for couples who jointly own one home.

Under the special regime, taxpayers can deduct 1.2 billion won ($897,000) from the assessed value of their home and receive additional tax reductions based on their age and how long they have held the property.

Applying for the special regime is not always the better option, however. Since the regime was introduced, the basic deduction has been raised from 600 million won to 900 million won per person, meaning some couples may be better off forgoing the special regime and instead claiming up to a combined 1.8 billion won in basic deductions — 900 million won each — as a two-person, one-household ownership arrangement.

"Taxpayers who are not familiar with tax law and are busy with their livelihoods had to log into Hometax themselves, run simulations, and decide on their own whether to apply or cancel," Lim said. "It was also difficult to verify whether the calculation results were correct, and elderly taxpayers in particular found it hard even to access Hometax in the first place."

Lim had attempted to enshrine the advance notification system in law through an amendment to the Comprehensive Real Estate Tax Act that he introduced in October 2024 while serving as a National Assembly member. The bill would have required the NTS commissioner to notify taxpayers of their projected special-regime tax amount by Oct. 31 of each year, but it did not pass. By taking office as NTS commissioner, he has now achieved the policy change roughly two years after first proposing it.

"In line with the government's proactive administration policy, the NTS will expand tailored guidance in areas where taxpayers find it difficult to make decisions on their own, so that they face less inconvenience and do not miss out on benefits they are entitled to," Lim said.