Korea's 2028 Home Tax: Joint-Owning Couples Are Not Multiple-Home Owners, But They Can Be Taxed Like Them

South Korea's Ministry of Economy and Finance has confirmed that married couples who jointly own a single home will not be reclassified as multiple-home owners under the comprehensive real estate tax, settling a debate that followed the 2026 tax reform plan ^[1][2]. The consequence that actually costs money is narrower: from 2028, a joint-owning couple in a regulated zone who does not apply for the single-household, single-home exemption is assessed on 80% of fair market value, the same ratio used for multiple-home owners ^[3].

The legal position is straightforward. The tax is levied on an individual basis, so when a couple splits ownership of one home each spouse is taxed as a standard single-home owner on their own share ^[4]. The ministry's language is that joint owners who are married "are standard single-home owners and are not regarded as multiple-home owners" for comprehensive real estate tax purposes ^[2]. Joint owners have been able to elect the single-household, single-home exemption since 2021, and that election survives the reform ^[5].

What changed is the ratio. Today the fair market value ratio is 60% for both standard joint ownership and the single-household, single-home exemption ^[6]. From 2028, exemption filers move to 70%, while joint owners of one home in a regulated zone who do not file move to 80% ^[7]. Regulated zones include all of Seoul and 15 districts in Gyeonggi Province ^[8]. So the exemption filing is worth 10 points of ratio, or a tax base roughly 14% smaller ^[9]. Non-resident joint owners have a second problem: their basic deduction shrinks, leaving some criteria less favorable than before ^[10].

For couples who live in the home, the election is a straight comparison ^[11]. A simulation by tax accountant Kwak In-song, comparing a single-household, single-home owner taking the maximum tax credit against resident joint owners each holding 50%, finds joint ownership equal or better up to an assessed value of 2.05 billion won, a market price of 2.93 billion won, under current rules ^[12]. From 2028 that crossover falls to 1.92 billion won assessed, a market price of 2.74 billion won ^[13] - roughly 130 million won lower in assessed terms ^[14]. The reason joint ownership wins at the bottom is that co-owners pay nothing up to 1.8 billion won in assessed value, a market price of 2.57 billion won, and above that they split the base ^[15].

Then the ordering flips twice. Between 1.92 billion and 3.2 billion won assessed, a band about 1.28 billion won wide ^[16], the exemption's 70% ratio plus its credit wins ^[17]. Above 3.2 billion won, joint ownership wins again, because the single-home credit is capped at 6 million won while the value of splitting the base keeps growing ^[18].

The worked examples show the size of the swing. For 2028, Lotte Castle Signiel - Jamsil's Lezents, at an assessed value of 2.39 billion won, comes out at 1.6 million won under joint ownership and 850,000 won with the exemption ^[19], a saving of 750,000 won for filing ^[20]. Acro River Park, at 4.14 billion won, comes out at 14.7 million won under joint ownership against 19.6 million won with the exemption ^[21], so joint ownership is 4.9 million won cheaper, about a quarter less ^[22].