The Korean National Tax Service (“NTS”) announced on May 14, 2026 that Commissioner Lim Kwang-hyun visited Hungary (Budapest), Belgium (Brussels) and the United Kingdom (London) from May 8 to 13, 2026, holding bilateral meetings with each country’s tax commissioner and signing Memoranda of Understanding on mutual assistance in tax collection (collection cooperation MOUs) with each. In this RSM Korea Newsletter, we summarize the key contents of the NTS press release and present RSM Korea’s views on the practical implications for your business. This document is a general informational summary prepared on the basis of publicly available information, and should not be construed or used as legal, tax, or accounting advice for individual matters. As outcomes may vary depending on specific facts and circumstances, independent professional advice should be sought before making any actual decisions.


 

■ Overview of the MOU Signings

These are not the first collection cooperation MOUs signed by the NTS. Prior MOUs were entered into with Australia (September 2025) and Indonesia (December 2025), and bilateral tax cooperation more broadly has long been conducted under existing instruments — most notably the “Exchange of Information” article of Korea’s extensive tax treaty network (covering approximately 98 jurisdictions as of December 2025). The recent signings, however, mark a meaningful geographical expansion of Korea’s collection cooperation network from the Asia-Pacific region into major European jurisdictions.


 

■ Key Policy Implications

The recent signings carry the following symbolic and policy significance:

• Geographical expansion of Korea's collection cooperation network from the Asia-Pacific region to major European jurisdictions.

• The Belgium MOU represents the first-ever bilateral tax commissioners' meeting and collection cooperation MOU between Korea and Belgium.

• The MOUs are paired with a newly emphasized simultaneous tax audit framework, under which both tax authorities may conduct coordinated audits and share investigative information on taxpayers with economic footprints in both jurisdictions.

• The NTS has accepted the invitation to participate in the Tax Debt Management Network, a working-level forum under the OECD Forum on Tax Administration (FTA), currently chaired by Belgium (existing Asian participants include Japan and Singapore).

• With Hungary, in addition to the collection cooperation MOU, the NTS also renewed its Working Agreement on Tax Administration Cooperation (originally signed at the 2nd Korea-Hungary Tax Commissioners' Meeting in September 2021) and exchanged digital tax administration practices, including the use of AI.

■ Recent NTS Policy Direction

According to the NTS press release dated April 27, 2026, the NTS recovered approximately KRW 33.9 billion across 5 cases through collection cooperation with three jurisdictions during the nine months following Commissioner Lim's appointment (July 2025) — a figure that accounts for the majority of the NTS’s cumulative collection cooperation results since 2015 (24 cases across 18 jurisdictions, totaling KRW 37.2 billion). This indicates that delinquent tax collection and cross-border enforcement have become core priorities of current NTS policy.

RSM Korea View

1.  The MOUs themselves are not a sudden departure: Korea has long had bilateral tax cooperation mechanisms in place. However, this signing should be read as a clear signal of policy direction — namely, the NTS's intent to actively enforce delinquent tax collection in a cross-border context.

2.  Particular attention should be given to the simultaneous tax audit framework, which goes beyond conventional Exchange of Information and enables coordinated audit activity in both jurisdictions.

3.  Korea's participation in the OECD FTA Tax Debt Management Network suggests that the NTS will increasingly leverage multilateral mechanisms in addition to bilateral cooperation.

 

■ Korea-Hungary (May 8, 2026)

Commissioner Lim held the 4th Korea-Hungary Tax Commissioners' Meeting with Ferenc Vágújhelyi, Commissioner of the Hungarian National Tax and Customs Administration. Hungary, the first Eastern European country to establish diplomatic relations with Korea, hosts more than 300 Korean companies, particularly in the battery and automotive sectors. The two sides newly signed a collection cooperation MOU and renewed the Working Agreement on Tax Administration Cooperation. Both authorities also shared digital tax administration practices, with Hungary expressing particular interest in Korea's big-data-based delinquency detection system and AI-driven tax evasion analytics.

■ Korea-Belgium (May 11, 2026)

Commissioner Lim held the first-ever Korea-Belgium Tax Commissioners' Meeting with Filip Van de Velde, Head of the Belgian Tax Administration. 2026 marks the 125th anniversary of diplomatic relations between Korea and Belgium. The two sides signed the first-ever bilateral collection cooperation MOU. Commissioner Van de Velde further proposed Korea's participation in the OECD FTA Tax Debt Management Network (currently chaired by Belgium), which Commissioner Lim accepted. The two sides also agreed to establish communication channels to address tax issues faced by companies operating in each jurisdiction, particularly in the biotech and secondary battery sectors.

■ Korea-United Kingdom (May 13, 2026)

Commissioner Lim held the 3rd Korea-UK Tax Commissioners' Meeting with John-Paul Marks, Chief Executive of HM Revenue and Customs. Prior to the meeting, Commissioner Lim convened a tax administration roundtable with Korean companies operating in the UK and conveyed their concerns directly to Commissioner Marks. The two authorities shared experiences on whistleblower reward programs and delinquent tax collection. They also signed a bilateral collection cooperation MOU to enable effective enforcement against cross-border tax delinquents, agreeing to actively cooperate on the recovery of assets located in each other's jurisdiction.

■ Profiles Warranting Heightened Attention

RSM Korea recommends enhanced compliance review for taxpayers falling within the following profiles:

• High-amount habitual delinquents holding assets or business operations in the signatory jurisdictions (Hungary, Belgium, UK) or earlier MOU jurisdictions (Australia, Indonesia).

• Transaction structures that may give rise to offshore tax evasion concerns, including the routing of Korea-sourced income through foreign-entity accounts without proper reporting.

• Multinational enterprises with economic footprints in both Korea and an MOU jurisdiction, which may fall within the scope of simultaneous tax audits.

RSM Korea View

1.  Multinational enterprises operating in both Korea and one of the MOU jurisdictions should re-examine the alignment between their legal/contractual structures and their actual economic substance, particularly with respect to cross-border intercompany flows.

2.  Where Korea-sourced income (e.g., royalties, service fees, technical assistance fees) is received through offshore entities, the supporting documentation — contractual arrangements, beneficial ownership analysis, and treaty entitlement — should be revisited.

3.  For taxpayers with outstanding Korean tax liabilities and overseas assets, a proactive review of voluntary settlement options is advisable before the NTS escalates to a collection cooperation request.

4.  Companies expecting cross-border tax audits should plan for the possibility of coordinated audit activity in both jurisdictions, and align documentation and audit-readiness accordingly.

■ References

▪  NTS Press Release (May 14, 2026): https://www.nts.go.kr/

▪  Korea Times (May 14, 2026), “Korea broadens overseas tax collection cooperation into Europe”: Link

▪  Korea Herald (May 14, 2026), “National Tax Service expands tax recovery cooperation with Europe”: Link

This document has been compiled by Shinhan Accounting Corporation (RSM Korea) based on the NTS press release dated May 14, 2026, to assist corporate tax managers. The contents are for general informational purposes only and should not be construed as legal, tax, or accounting advice. Please consult your tax professional for guidance on individual matters.