It is an atypical contract, but is allowed under protection Act. 1,255 C.C and 50 of the C. Commerce, concerned of the Anglo-Saxon legal system, characterized by the consensual, bilateral, that is to say generating doctrine like of reciprocal obligations, synallagmatic (with interdependence of benefits acting each like cause of the other), of continued duration and in which reciprocal obligations interchange. The contract of exchange of types of interest consists of the agreement to interchange on a stated capital of reference and nonreal (notional) the resulting amounts to apply a coefficient different for each contractor denominated types from interest (although they are not such, in strict sense, because it does not have, in fact, agreement of capital loan) limiting the contracting parts, in agreement with the respective terms and agreed types, to interchange partial payments during the use of the contract or, only and more simply, to eliminate periodically, by means of compensation, such interchanges being in favor of one or the other contractor a indebted balance or, vice versa, creditor. The right to the information in the banking system and the trusteeship of the banking transparency is basic for the operation of the market of banking services and its purpose as much is to obtain the efficiency of the banking system like tutelary to the subjects that take part in him (the banking client), mainly, to traverse as much of the precontractual information, in the previous phase to the conclusion of the contract, like in the contractual phase, by means of the indispensable contractual documentation. In this sense the appointment of the 48,2 of the L.D.I.E.C is forced. 26/1.988 of 29 of July and its development but the one that real and indeed agrees to the case is the one of Law 24/1,988 of 28 of July of the Stock market when coming considered by the Bank from Spain and the C.N.M.V to blame within its scope (SAP Asturias of 27 of January of 2010).
And examined the norm of the stock market it positively surprises the granted protection the given client the complexity of that market and the intention decided that it is developed with transparency but surprises, mainly, the tedious thing of the normative development on the treatment due to give the client, with special incidence in the precontractual phase. The excellent information as far as the risk of the operation is regarding the forecast reasoned and reasonable of the future behavior of the referential variable type. Therefore the client only can value ” with knowledge of causa” if the supply of the Bank, in the conditions of types of interest, propose period and calculation, satisfies to or not its interest. So that if this information has not been facilitated, the contract can be attacked by the banking client trying the invalidity of swap.