The article is devoted to the analysis of the consequences of a bank's refusal to provide a loan (tranche) for individuals who have provided collateral. For the first time, a special study has been conducted on the ways to protect the interests of guarantors and pledgoras “for someone else's debts” when a bank terminates lending under credit line agreements. As a result of this study, the author concludes that it is necessary to develop a doctrine of reasonable expectations for the guarantor and pledgoras regarding the borrower's receipt of the full amount of the loan. The novelty of this work lies in the justification of the position that the refusal to provide a tranche should be considered as a transaction that infringes on the scope of the security relationship.