Sa’if 1, Mechaber: Two persons borrowed from one lender or purchased something from one seller. (Rama: Or received a deposit in trust from one depositor.) Irrespective of whether the transaction was recorded in writing or not, each is deemed an arev, a guarantor for the obligations of the other. This is the halacha even if there was no express stipulation to this effect. Accordingly, if one of the borrowers has no assets, the lender may collect the entire amount of the loan from the guarantor. If, however, both borrowers have assets, all the laws of a guarantor apply and the lender may not collect the entire loan from the guarantor but must collect half from each.
If, however, the two borrowers explicitly stipulated that each was an arev kablan for the debt of the other, the lender can collect the entire loan from either of the two borrowers he chooses. The borrower who repaid the lender the entire loan has a claim against the co-borrower for repayment of his half of the loan. (Rama: Accordingly, if two persons borrowed and one of them repaid the entire loan, he is deemed to have repaid fifty percent of it on the co-borrower’s behalf.)
Ner Eyal: The Sma points out that the halacha in the case discussed in this Siman 77:1, where there are two co-borrowers, is different from the case to be discussed in Siman 77:3, where there is only one borrower whose loan is guaranteed by two guarantors, neither of whom borrowed any money.
If two persons who did not borrow any money guarantee the repayment of a loan made to a third person, the halacha is that the lender may proceed to collect the entire amount of the loan from either of the two guarantors without first having to attempt to collect half of the loan from each. That is because such guarantors were not parties to the underlying loan transaction. Unlike the guarantors discussed in this Siman 77:1, the guarantors to be discussed in Siman 77:3, never borrowed any money from the lender. Accordingly, the lender cannot view them as primarily responsible for a portion of the loan. Rather, each such guarantor independently undertook, as a favor to the borrower, to pay the entire loan in the event that the borrower would default.
It is as if each such guarantor gave a pledge to the lender for the entire amount owed by the borrower. A pledge, by definition, is security for the entire loan. There is no pledge for half a loan. The lender to be discussed in Siman 77:3 may, therefore, proceed against either of the guarantors for the entire amount. After honoring the guarantee and repaying the entire loan, the guarantor may recover half of the loan from the other guarantor. In the case discussed in this Siman 77:1, however, the guarantors are also the borrowers. They are each party to the underlying transaction. The primary obligation of each is to repay half the loan he received. Accordingly, the lender must first try to enforce the primary obligation against each borrower before he may sue the other borrower in his capacity as guarantor.
The result in this Siman 77:1 would be different if the two co-borrowers had agreed to be an arev kablan for each other. The difference between an ordinary arev, an ordinary guarantor, and an arev kablan lies in the language used by the guarantor. If the guarantor says to A, give B $1,000 and I will pay you back, he is an arev kablan. As such, A can proceed to collect the money directly from the arev kablan without attempting to first collect from B. This is because the language used did not include any words indicative of a loan. It was more indicative of a gift. It is as if the arev kablan appointed A as his agent to gift money to B. Having fulfilled his agency and advanced the money out of his own pocket, B, the agent, can go straight back to the principal to be reimbursed. If, however, words indicating a loan are used, such as “please lend B money and I will pay you back,” the rules of a regular arev apply. Accordingly, A must first attempt to collect from B before proceeding against the arev.
Even if the guarantor was not deemed an arev kablan, if the loans were recorded in a promissory note that stipulated the lender can collect from the guarantor first, without proceeding against the co-borrower, he may do so.