Hello, I am Attorney Eom Sang-yoon of Cheongchul Law Firm.

When a company or individual becomes the subject of a criminal investigation, legal advice documents, opinions, emails, and the like prepared to receive assistance from counsel may contain the core details of the case. If such materials are exposed as-is during a search and seizure by an investigative agency, the client would inevitably hesitate to tell counsel the facts honestly, and ultimately the constitutional right to assistance of counsel would be rendered hollow.

Against this backdrop, discussions on introducing attorney-client privilege (Attorney-Client Privilege, hereinafter "ACP") have continued for a long time. On 2026. 1. 29., an amendment bill to the Attorneys-at-Law Act passed the plenary session of the National Assembly, and ACP was formally introduced into Korean law. Meanwhile, around the same time, the Supreme Court issued a decision clarifying that ACP is protected by the constitutional right to assistance of counsel. Today, let us look at the specific content of the introduction of ACP and its practical implications.

Amendment to the Attorneys-at-Law Act and Introduction of ACP

Under the former Article 26 of the Attorneys-at-Law Act, only an 'duty' not to disclose confidential information learned in the course of duties was imposed on attorneys, and it did not expressly provide a 'right' for clients not to disclose communications with their attorneys. As a result, investigative agencies and others interpreted the attorney's duty of confidentiality as merely a duty that attorneys themselves must observe, and there were clear limits on clients or attorneys refusing search and seizure or requests to submit materials on that basis. This has been pointed out as a weakness in our legal system, in contrast to the fact that most OECD member countries, except Korea, explicitly recognize ACP.

Accordingly, the introduction of ACP had been continuously pursued, and the recently amended Attorneys-at-Law Act newly established Article 26-2 (Right to confidentiality, etc.) and codified ACP. The core of the amended law is that by converting confidentiality into a right, both attorneys and clients gain an affirmative right not to disclose communications. In addition, the protected materials are broadly defined as ① confidential communications between attorney and client, and ② documents and materials (including electronic forms) prepared by an attorney for litigation, investigation, or inquiry in connection with a retained case, so not only opinions prepared by attorneys but also emails, messenger chats, advisory memos, and litigation preparation documents exchanged between attorneys and clients may all be protected.

The main amendments to the Attorneys-at-Law Act regarding ACP are as follows.

1. The amended law grants the right to refuse disclosure of materials not only to attorneys but also to clients and persons intending to become clients, so communications during pre-retainer consultation before formal engagement are also included in the scope of protection.

2. The protected materials are divided into (i) confidential communications made between attorney and client for the purpose of assistance regarding a legal case or legal affairs (paragraph 1), and (ii) documents and materials prepared by the attorney for litigation, investigation, or inquiry in connection with a retained case (paragraph 2).

3. However, disclosure is exceptionally permitted in cases where (i) the client voluntarily consents to disclosure, (ii) the attorney is involved in the client's criminal or unlawful conduct, or (iii) there is another compelling public interest need (paragraph 3). This can be seen as a safeguard to prevent ACP from being abused as a means of concealing unlawful conduct.

Admissibility of Evidence Collected in Violation of ACP

The amended Attorneys-at-Law Act introducing ACP will take effect on 2027. 2. 19., one year after its promulgation, but under Addendum Article 2, the amended law also applies to communications made or materials prepared before the effective date.

Meanwhile, before the amended Attorneys-at-Law Act took effect, the Supreme Court expressly held through 2024Mo730 decision dated 2026. 2. 20. and 2025Do4422 judgment dated 2026. 2. 26. that seizure of legal advice documents related to a criminal case between counsel and a suspect is, in principle, not permitted. However, it held that seizure is exceptionally allowed only when there is a compelling public interest need, such as (i) the client consents to the seizure, or (ii) the attorney is in a co-principal relationship with the suspect/defendant or involved in the crime or other unlawful conduct.

In particular, the 2025Do4422 judgment held that where communications materials with counsel unlawfully seized (a recording of a call with counsel) are primary evidence, secondary evidence derived therefrom also, in principle, lacks admissibility. Thus, even if the defendant was shown the materials or questioned based on their content, it was determined that such evidence constitutes secondary evidence based on illegally collected evidence and is not admissible.

These decisions confirm that ACP is protected not merely as a statutory right but as part of the constitutional right to assistance of counsel, and therefore ACP in criminal proceedings is expected to apply immediately regardless of whether the amended Attorneys-at-Law Act has taken effect.

Practical Implications

As above, ACP is already being applied, and accordingly substantial practical changes are expected. Corporate legal personnel, among others, need to be familiar with the scope protected by ACP and respond appropriately during investigations and similar processes.

First, to receive ACP protection, it is very important to manage legal advice materials in a form and appearance that identifies them as such. It is necessary to keep ordinary business materials and legal advice materials clearly separate, add markings such as 'Attorney-Client Privilege' or 'Subject to Confidentiality' to advisory documents, and, where possible, conduct communications with the attorney as the direct recipient so that they are clearly distinguishable from ordinary materials.

If a search and seizure is actually carried out, the attorney should immediately object on-site to the seizure of materials protected by ACP and clearly record the objection in the seizure list and procedural record. Even if exclusion of illegally obtained evidence is asserted afterward, once the investigative agency has already become aware of the contents, it is difficult to fully restore the infringement of the right of defense. In the process of cellphone forensics, it is necessary to actively state objections so that recordings of calls with counsel, emails, and messenger chats are not included among the items to be filtered.

However, care must be taken to note that ACP by no means means absolute immunity for all communications. Article 26-2, paragraph 3 of the amended Attorneys-at-Law Act expressly sets forth certain exceptions, and in particular, ACP does not apply where the attorney is involved in the client's crime or unlawful conduct. In other words, ACP is a system that protects legitimate legal advisory activities; it cannot be used as a means to conceal unlawful conduct.