Can a phone conversation recorded without permission be used as recording evidence?

To get straight to the point, recording a conversation between yourself and the other party as one of the parties to the call is not illegal.

Article 3, Paragraph 1 of the Protection of Communications Secrets Act prohibits eavesdropping or secretly recording the conversations of others, and a violation may result in criminal punishment.

However, recording by the party themselves does not fall under this.

The Supreme Court has also ruled that "it is not illegal for one of the parties to a phone conversation to record the contents of the conversation with the other party."

Therefore, as in your case, where you personally had a conversation, induced the other party to mention the debt, and recorded it, this is not illegal, and the recording can be recognized as recording evidence in civil litigation.

However, infringing on the other party's personal rights or disclosing the recording contents may become a separate issue, so it is good not to distribute the recording evidence outside of court and use it only for trial purposes.

In addition, the recording contents must be configured to be directly related to legal issues, and to reduce the possibility of being interpreted unfavorably in court, expert advice is essential.

Please note that recording evidence to be used in actual litigation is advantageous to prepare strategically with an attorney from the collection stage.