Q: Does signing a rental contract or confirming via e-mail or the internet make a rental agreement binding?

A: Real estate is acquired through shtar, a contract that the seller hands to the buyer stating that he sells him the property. Similarly, a rental contract that the landlord hands to the renter for the purpose of finalizing the agreement would make it binding (C.M. 191:1, 3; 315:1).

Simply signing a rental contract, however, would not be included in shtar if it were not handed over. Nonetheless, it would likely be binding nowadays based on situmta, the common commercial practice (C.M. 201:1).

Similarly, any common commercial practice would make the agreement binding. The Rosh writes that a practice to finalize through speech alone, with no additional action, is not binding, whereas the Radbaz rules that even such a practice is binding (see Minchas Pitim 176:3). The current practice is that an e-mail or web confirmation is also binding.