Case: The plaintiff (=pl) rented an apartment and paid the rent until the final date of the contract – 15.09.11. The defendants (=def) agreed to rent it from the landlord from the same date and were also paying for their old apartment until that day. Def wanted to enter the apartment as early as possible (before the contract’s beginning date), and the landlord had pl and def work out between them arrangements for the transfer of the key and the practical elements of changing renters. Pl gave def the keys on 01.09.11. Pl received permission from def to leave a modem in the apartment, and the modem is now not to be found. Pl demands of def to pay half of a month’s rent (1,750 shekels) to him to compensate pl for use of the apartment before 15.09.11, as pl had paid the landlord for that time and def was using it. Pl also demands payment of 358 shekels for the modem which was lost under def’s guard. Def counters that he too was paid up in his old apartment until 15.09 and thus he did not gain significantly by receiving the key early. Therefore, he should not have to pay for the use of the apartment.

Ruling: Had there not been any agreement between pl and def, beit din would have to analyze the case in regard to the question of one who occupies another’s property without paying. In such cases, some of the factors that determine whether the occupier is required to pay are whether he had financial gain and whether the property was slated to be rented out. As it turns out, though, the question of payment for the interim period came up. Pl demanded payment, which def thought was not necessary; pl offered a compromise, but no agreement was arrived at.
While there is a big question whether one who uses an occupied property has to pay after-the-fact, a property owner can demand payment, from the outset, before agreeing to allow someone to use his property (Rama, Choshen Mishpat 363:6). This is because if the owner wanted, he could have rented out the property to someone else, so that even if he did not want to, he could still demand payment. Therefore, since def was aware of pl’s demand, they became obligated to pay when they decided to nonetheless live there. The fact that def objected because they thought the demand was immoral is not relevant.
Regarding the lost modem, one could try to analyze whether def was a hired watchman or a watchman for free, which impacts on the degree of responsibility. However, def’s claim is that the modem was missing before he moved in. There were workers who had the key and access to the apartment. Therefore, even though def agreed to be a watchman when he moved in, we have no proof that there was a modem present at that time, which might have obligated him.
Therefore, def has to pay pl 1,750 shekels.