민법 제449조 제2항에서는 “채권은 당사자가 반대의 의사를 표시한 경우에는 양도하지못한다. 그러나 그 의사표시로써 선의의 제3자에게 대항하지 못한다”고 규정하고 있다. 이규정의해석에관하여기존의다수설과판례는양도금지특약이있는경우채권의양도성이상실되어 채권양도가 일어나지 않지만, 거래의 안전을 보호하기 위하여 선의의 제3자에게무효를 주장할 수 없다고 해석한다. 이를 물권적 효력설이라 한다. 그러나 채권의 재산적성격과양도성을제고하는것이국제적흐름이라는이유로양도금지특약있는채권의양도도유효하고다만악의의양수인에대하여채무자는이행거절을할수있다고해석하는채권적 효력설이 강력하게 주장되었다. 이에 따라 민법 제449조 제2항에 대한 개정의견이 제시되기도 하였다.
그러나채권적효력설은다음과같은의문점이있다. 첫째, 현행민법규정은‘양도하지못한다’고 명시적으로 규정하고 있는데 이를 ‘양도할 수 있다’고 해석할 수 있는지 의문이 든다. 민법에서 채권양도금지특약에 관한 별도의 규정을 둔 이유는 채권의 상대성 원칙이 채권양도에그대로적용될경우채권양도금지특약을믿은채무자의신뢰를깨뜨릴수있다는이유와, 채권양도금지특약의 효력을 당사자에게만 귀속하는 것은 제3자에게 영향을 미칠수 있으므로 채권의 상대성 원칙을 고수할 수 없다는 취지라고 해석하여야 할 것이다. 둘째, 채권적 효력설은 양도금지특약에 관하여 채권자와 양수인의 이익을 지나치게 강조하는해석이라 생각된다. 양도금지특약 있는 채권양도의 효력과 관련하여 이익형량을 해야 할자는 채권자와 채무자이지, 양수인의 이익을 지나치게 강조하는 것이 타당하다 할 수 없을것이다. 셋째, 채권적효력설은양도금지특약있는채권을양도한경우채권양도자체는유효하고, 채권자는 양도금지특약 위반에 대한 채무불이행책임을 부과하면 된다고 설명한다.
그러나 채권자가 부담하는 채무불이행책임은 손해배상책임인데 채무자에게 손해가 발생하지 않았다면 채권자에 대한 손해배상청구는 실익이 없게 된다. 양도금지특약 위반에 대한 법적책임으로는 적절하지 않다고 할 것이다. 넷째, 채권적 효력설은 채권적 효력설이 국제적 흐름에 부합한다고 한다. 그러나 국제물품거래나 국내의 상거래로 인한 채권이나 금전채권등일정한범위의채권을넘어지명채권전체에대하여채권적효력설로전환하는것이 국제적 흐름이라고까지 보기 어렵다고 할 것이다. 다섯째, 민법개정시안에 의하면 채권적 효력설에 따라 제449조의2를 신설하여 “채권양도를 금지하거나 제한하는 약정은 그에반하여행해진채권양도의효력에영향을미치지아니한다. 다만, 양수인이그약정이있음을 안 경우에는 양수인에게 대항할 수 있다”고 개정할 것을 제안하고 있는데, 만약 양수인이 악의인 경우 채무자는 양수인에게 채무를 이행할 필요가 없게 되고, 채권양도가 유효이므로 채권자에게도 채무를 이행할 필요가 없게 되는 문제점이 발생할 가능성이 있다.
현행민법의해석상 양도금지특약이있는경우 채권의양도성이상실되어 채권양도가일어나지않지만, 거래의안전을보호하기위하여선의의제3자에게무효를주장할수없다고해석하는 것이 타당하다 할 것이다.
Subsection 449(2) of the Civil Act provides that “Where the parties have declared a contrary intention, a claim shall not be assigned: Provided, That such declaration of intention, cannot be set up against a third person acting in good faith” Regarding the interpretation of this subsection, the existing majority theory and precedents interpret that if there is a special agreement on prohibition of transfer, the transferability of the claim is lost and the transfer of the claim does not occur, but in order to protect the safety of the transaction, the invalidity cannot be claimed against a bona fide third party. This is referred to as the property effectiveness theory. However, on the grounds that improving the property character and transferability of claims is an international trend, the claim effectiveness theory is strongly asserted, which interprets that the transfer of receivables with a special agreement on transfer prohibition is valid, but the debtor can refuse performance against the malicious assignee. Accordingly, an opinion on amendment to subsection 449(2) of the Civil Act was presented.
However, the claim effectiveness theory has the following questions.
First, because the current subsection of Civil Act explicitly stipulates that “non-transferability”, it is questionable that this subsection may be interpreted as “transferability.” The reason why the Civil Law has a separate provision on the special agreement for the prohibition of the transfer of receivables is that if the principle of relativity of claims is applied to the transfer of receivables, it may break the trust of the debtor who believed in the special agreement for the prohibition of the transfer of claims, and if the effect of the special agreement for the prohibition of the transfer of receivables is only applied to the contracting parties because it cannot affect a third party, the principle of relativity of claims cannot be adhered.
Second, the claim effectiveness theory is thought to be an interpretation that overemphasizes the interests of the creditor and the transferee in relation to effect of transfer of receivables with special agreement for prohibition of transfer. It is the creditor and the debtor who have to weigh the profits in relation to effect of transfer of receivables with special agreement for prohibition of transfer, so it would not be reasonable to overemphasize the interests of the transferee.
Third, the claim effectiveness theory explains that transfer of receivables with special agreement for prohibition of transfer is valid, and the creditor only needs to impose liability for default on the violation of the special contract for non-transfer. However, if the creditor's default is liable to the damages which debtor does not suffer damages, the claim for damages against the creditor will be of no practical benefit. Therefore, it is not appropriate as a legal responsibility for the violation of special agreement for prohibition of transfer.
Fourth, it is said that claim effectiveness theory conforms to the international trend.
However, it would be difficult to say that it is an international trend to convert all named claims beyond a certain range of claims, such as international goods transactions or domestic commercial transactions, or monetary claims, to the theory of claim effectiveness.
Fifth, according to section 449bis of the proposed amendment to the Civil Law, “Agreements prohibiting or restricting the transfer of receivables do not affect the validity of transfer of receivables. However, if the assignee is aware of the existence of the agreement, it may not enforceable and because assignment of claim is valid, there is a possibility that creditors will not have to pay their debts.
According to the interpretation of the current Civil Act, it should be interpreted that if there is a special agreement on prohibition of transfer, the transferability of the claim is lost and the transfer of the claim does not occur, but, in order to protect the safety of transactions, it would be reasonable to interpret that invalidity cannot be claimed against a bona fide third party.