delivered the opinion of the Court.

Some time in March 1950, the domestic corporation Suers, de Lavandero, Inc. owed the sum of $22,232.82 to several *576commercial firms of this city. In view of the fact that its financial condition did not permit it to pay on their due date the obligations contracted, Frank Santiago Lavandero, president of that corporation, wrote to the adjuster of the Cámara Insular de Comerciantes Mayoristas proposing a plan for the payment of those debts. In that connection, he stated that he was willing to pay the full amount thereof “through that entity” in monthly instalments of not less than $500, and to secure the payment by a mortgage on the equipment and furniture of the business. He also proposed that “the expenses and fees of the Cámara Insular de Comerciantes Ma-yoristas shall be on our account (of the corporation) in order that you (the creditors) may collect your money in full.” This proposal was accepted, and on the following July 18 the corporation issued a promissory note in favor of the Cámara and constituted a chattel mortgage which was duly recorded in the Registry of Property of Rayamón.

On February 9, 1951, the Cámara cancelled the promissory note issued by the corporation and also the mortgage constituted as already stated, upon payment in full of the total amount, “by means of other guarantees which today have substituted the present obligation.” The corporation was thus able to dispose freely of the mortgaged chattels. It is well to note that Santiago Lavandero procured the cancellation referred to by proposing that the corporation’s unpaid balance be reduced to 70 per cent only of the outstanding principal, out of which he paid part in cash and issued an obligation for the sum of $7,239.64 1 in favor of the Cámara *577to guarantee the balance, which was signed by codefendant Ramón Cobián Chinea, as cosurety.

Santiago Lavandero paid four monthly instalments on the promissory note totalling $1,608.80, but since he failed to pay two or more instalments on the obligation the Cámara went to court to recover the balance of $5,630.84, in accordance with the express authorization granted by an ac*578celerated-maturity provision which had been incorporated as one of the conditions of the note. In the answer defendants Santiago and Cobián admitted expressly the execution and delivery of the note, alleged several defenses which are actually aimed at challenging the capacity of the plaintiff entity to file the complaint,2 and defendant Santiago filed a counterclaim for recovery of the sum of $11,108.80 which he had paid to the Cámara on the occasion of the substitution of the debtor agreed upon, as already stated, and the instal-ments paid on the note the collection of which is sought.

Appeal was taken from the judgment sustaining the complaint. All the errors assigned hinge on the capacity of the plaintiff association to sue, to bind itself, and to be assignee of the credits of its members and procure their collection.

1. Just a few days ago we passed upon a similar issue on the challenging of the entity Cámara Insular de Comercian-tes Mayoristas to act as assignee of the credits of its members and seek collection thereof through judicial channels. We rejected the debtor’s position, which is identical with that maintained by defendants-appellants. After examining the applicable legal provisions and the by-laws of that institution, which we need not recite here, we stated in Cámara Insular, Etc. v. Anadón, S. en C., ante, p. 360, that *579the plaintiff had authority to acquire the credits of its members, even though there was no consideration in the assignment and even though the assignors retained certain rights to any amount that might be recovered. We added that the debtor is in no position to challenge the assignment made, since such assignment does not create new obligations as respects him. In the instant case the situation is still more difficult for defendant, since he can not challenge personally the original assignment of credits against the corporation made by the members in favor of the Cámara, and, furthermore, as a question of reality the original debtor, Suers, de Lavandero, Inc., was relieved from the payment thereof,3 and consented to the novation of the obligation, thereby convalidating it, for such consent expresses the purpose not to use the action of nullity. VIII Manresa, Comen-tarios al Código Civil Español 398-99 (4th ed. 1929).

2. Since the note in question was executed by defendants in favor of the plaintiff, they can not assert lack of capacity of the creditor entity in order to evade payment of the obligation which they not only assumed voluntarily, but which arose in the judicial business as a result of suggestions made by the principal debtor himself. B. Fernández Hnos., Sucrs. v. Ortega, 51 P.R.R. 428 (1937); Succrs. of Canals Bros. & Co. v. Heirs of Quiñones, 46 P.R.R. 512, 518 *580(1934); Succr. of Schluter & Co. v. Hernández et al., 36 P.R.R. 58 (1926). A similar situation was considered in Spokane Merchants’ Association v. Olmstead, 327 P.2d 385 (Idaho 1958). In that case several creditors of the Olmstead spouses assigned their claims to the plaintiff association, a merchants’ association of the locality; the debtors assigned their assets in the business in favor of the plaintiff, for the benefit of the creditors. It was held that the acknowledgment by the wife prevented her from challenging later the existence and capacity of the plaintiff entity. See, in particular, Royal Bank of Canada v. Iglesias, 46 P.R.R. 157 (1934); also, Kelly v. Kosuga, 358 U.S. 516 (1959). On the estoppel of the defendant to allege lack of capacity of the plaintiff, see Centro de Dependientes v. Montalvo, 72 P.R.R. 381, 384 (1951). Furthermore, the action of defendant Santiago in filing a counterclaim against the Cámara for the recovery of money paid to the latter, precludes him from questioning the plaintiff’s capacity. Flash Cleaners v. Columbia Appliance Corp., 319 P.2d 454 (Cal. 1957); Brandtjen & Kluge v. Biggs, 288 P.2d 1025 (Ore. 1955); Bell v. Commercial Investment Trust Co., 246 Pac. 1102 (Okla. 1926).

3. The averment that there was no consideration in the execution of the promissory note object of the present action is without merit, because the obligors did not receive money or properties from the creditor in exchange for the obligation. This case is an example of subjective novation by change of the debtor, that is, the substitution of an obligation for a subsequent obligation which extinguished the old one, which is performed by changing the obligor with the express consent of the creditor. On necessity of the creditor’s consent, see Ríos v. Rosaly, 50 P.R.R. 652 (1936); Bou v. Colorado, 24 P.R.R. 125 (1916). Specifically, the transaction is one of delegation, that is, when the debtor (the corporation) offers and the creditor accepts a third party (Santiago and Cobián) who consents to the substitution, in con*581tradistinction to the modality of expromissio which operates when the substitution of the debtor is made with the spontaneous intervention of a new debtor who takes the place of the old debtor, without his consent, but with that of the creditor. Section 1157 of the Civil Code (31 L.P.R.A. § 3241); IY-I Puig Peña, Tratado de Derecho Civil Español 350 (1951); 3 Castán, Derecho Civil Español, Común y Foral 318 (8th ed. 1954); VIII Manresa, Comentarios al Código Civil Español 392 (4th ed. 1929); Velázquez, Obligaciones y Contratos Se-gún la Legislación y la Jurisprudencia Puertorriqueña (University of Puerto Rico, mimeograph, 1939, pp. 265, 269-74) ; De Cossio, La Transmisión Pasiva de las Obligaciones, a Tí-tulo Singular, 1 Anales de la Academia Matritense del Nota-riado 187-206 (1943). Regarding the consideration of the new obligation of the delegated debtor (the defendants) in favor of the delegatee (Cámara Insular de Comerciantes Ma-yoristas), says Professor Velázquez at p. 273:

“The obligation assumed by the party delegated with respect to the delegatee has a consideration, not in the personal relations arising between them, but in the relations which join the party delegated and the party delegating. The party delegated contracts an obligation to the delegatee to make a gift, a loan, or a payment to the party delegating. The delegatee may even be unaware of the purpose sought by the party delegated. Thus, in his relations with the delegatee, the obligation assumed is separate from its consideration. It is an abstract obligation.”

On the other hand, we have held that where a promissory note is subscribed in substitution for other prior obligations, the fact that no money or property was received from the creditor by virtue of such note does not preclude the existence of a consideration therefor. National City Bank v. Martínez, 41 P.R.R. 162 (1930); Roig Commercial Bank v. Valladares et al., 38 P.R.R. 393 (1928); Commercial Bank v. Arguinzonis et al., 35 P.R.R. 260 (1926).

4. We need not discuss other collateral questions raised in the elaborate brief for appellants, for in the final *582analysis they all relate to those we have already considered. Regarding the legal services which the Cámara Insular de Comerciantes Mayoristas allegedly provides to its members, see The Unauthorized Practice of Law by Lay Organizations Providing the Services of Attorneys, 72 Harv. L. Rev. 1334 (1959), It can not be denied that defendant Santiago derived a personal benefit from the cancellation of the mortgage by the Cámara, which the corporation Suers, de Lavan-dero, Inc. had constituted. This fact enabled him to sell on more advantageous conditions the shares which he owned in that corporation and to engage, according to his own testimony, in more lucrative activities. Moreover, if we adopted the solution proposed by him, we would in fact prejudice those persons who trusted in the representations made to them and which prevented them from seeking by other means collection of that which was lawfully due to them. Although this was not the deliberate purpose of Santiago’s acts, such would be the result.

The judgment rendered by the Superior Court, San Juan Part, on April 4, 1957, will be affirmed.