My tenant is occupying an apartment without a lease for $700 a month, which is a low price in this market. The higher-end price for such an apartment is about $900. Someone approached me and told me that he’ll pay $1000/month for the apartment - but he needs it at the beginning of the next month. If he can’t have the apartment at the beginning of next month, he’ll find another place.

Q: Can I tell my current tenant that he must move out now? If I halachically may not, may I tell him that during the time that he has the right to remain there, I expect him to pay me $1000 - the amount the potential tenant would pay?

A: Shulchan Aruch (C.M. 312:5) writes that when Reuven leases property to Shimon with no specified lease duration, he must give notice to Shimon before demanding that he vacate the property. Depending on market conditions, the time frame may be generally thirty days to one year. This halacha clearly states that you may not demand that your tenant move out at once. The next question is whether you may charge your tenant $1000/month for the period of notice. Shulchan Aruch (C.M. 312:9) adds a vital qualification to the earlier ruling: although a landlord must give his tenant proper notice to vacate the property, if the rental market increases, the landlord may give his tenant an ultimatum, either you pay the higher rent or vacate the property right away. This indicates that you may be allowed to inform Shimon that if he wants to stay for the time granted by Chazal, he must pay $1000. However, the application here may be different. Shulchan Aruch refers to a circumstance in which the market increased. In your case, the market hasn’t changed; it is just that someone is willing to pay a price above market value. This case is disputed in halacha. Some rule that Chazal did not grant the tenant the right to remain if it would cause a loss to the landlord, and the landlord may raise the rent of his present tenant (Paamonei Zahav CM 312:5). Others rule that rent that’s higher than market value is not a loss that permits the landlord to charge the present tenant and is against the expectations of the tenant who relied on you to rent it to him for its value (Mateh Yosef CM 2/2). Due to the fact that this is subject to debate, you cannot demand that your tenant pay $1000 for the time that he remains in the apartment. However, since the actual market value here varies between $700 and $900, it is our opinion that you may raise the rent to $900. Your present tenant might expect you to adjust it if you’d find another tenant who is willing to pay a common market price.