A. On March 2017, the Korea International Cooperation Agency bid “the selection of a supplier of machinery and equipment for the construction project of a special school with a defected Cheongman-man,” and the Defendant participated in the said tender and was selected as a successful bidder.

On April 7, 2017, the Defendant entered into a contract with the Korea International Cooperation Agency and the Korea International Cooperation Agency to supply equipment and materials for the said project (hereinafter “instant equipment and materials”).

B. On March 28, 2017, the Plaintiff entered into a contract with the Defendant and the Plaintiff to supply the instant equipment (hereinafter “instant supply contract”).

around May 16, 2017, the Defendant finally determined the amount that the Defendant shall pay to the Plaintiff according to the instant supply contract as KRW 250,026,408 (including value-added tax).

C. Meanwhile, the provision on the terms of payment under the instant supply contract is as follows.

(hereinafter referred to as “instant payment clause”). After completion of domestic supply (after examination), 80% of the cost of equipment and materials shall be paid, and the payment shall be completed within 15 days after completion of delivery of 20% of the remainder after completion of on-site installation of equipment and materials, and 15% of the overdue interest rate shall be paid in the event of failure to implement the payment.

The Plaintiff supplied the instant equipment to the Republic of Korea on May 26, 2018, as prescribed by the instant payment clause, and received an examination, and completed installation of the instant equipment on or around August 9, 2017.

E. However, the Defendant paid to the Plaintiff a total of KRW 220 million, including ① KRW 100 million on July 4, 2017, ② KRW 80 million on August 31, 2017, ③ KRW 40 million on September 12, 2017.

[Ground of recognition] Facts without dispute, Gap evidence Nos. 5 through 8 (including branch numbers, if any) and the ground for a claim to determine the purport of the whole pleadings. According to the above facts, the defendant's total amount of 30,026,408 won (=250,026,408 won - 220,000,000 won as the unpaid payment to the plaintiff.