Monetary, Interpersonal Laws and Din Torah (10)
Multiple Prospective Tenants [or Landlords]. Often, there are a number of prospective tenants competing for the same house. If the landlord and one tenant have made a definite verbal agreement to go ahead with a deal, another would-be tenant is not allowed to try and get it for himself, even by offering a higher price. This is known as "עני המהפך בחררה" (1). Some Poskim hold that even if they are close to a final agreement with a bit more bargaining to finish, and it seems certain that they will soon agree, another is not allowed to step in. R’ Moshe Feinstein zt”l rules like this opinion (2). This halacha is talking about competing buyers, but it applies equally to rentals. This halacha, according to most Poskim, is based on the fact that the second person could [albeit with tircha] find another comparable house. Therefore, if this is an exceptional chance, either in price or other features that he cannot find elsewhere, there is no issur to compete till a kinyan is made. [Once a kinyan is made the parties cannot back out.] Although this is the basic halacha, the Shulchan Aruch Harav says that a person who wants to do the best should be concerned about the minority opinion that even by an exceptional chance one should not push the first one out.
What Constitutes a Kinyan? The accepted practice nowadays is to finalize a lease with a signed contract. The contract should clearly state this. The more details a contract has can prevent disagreements in the future. It is a good idea to get a Talmid Chacham to look over the agreement before signing to make sure that his interest is fully protected. Classically, paying the first rental fee is also considered a kinyan. However, there are two opinions if nowadays when documents are assumed to be the final step, if a payment is still considered a kinyan (3). A security payment is not considered a kinyan. If one moves in or starts making improvements to the house, such as hanging shades, it is a kinyan (4). The kinyan obligates both parties to the details in the lease till the termination of the lease which should be clear in the contract. Once a lease expires, there is no automatic renewal unless the lease itself has a clause included that specifies details about renewals.
(1) שו"ע חו"מ רל"ז (2) אגרות משה חו"מ א:ס (3) מנחת פתים חו"מ קצ"ב (4) שו"ע חו"מ קצ"ב