The law requires the landlords permission, otherwise you would have a illegal sublet that could end up in a lawsuit. Upvote A rent controlled tenant who is not occupying an apartment pursuant to an existing lease cannot sublet the apartment without the owner's written consent.The procedure for subleasing is quite complicated. If your landlord decides to deny your sublet request, the denial must be reasonable. Your landlord cannot unreasonably withhold consent to sublease. Most leases prohibit subletting, or only allow it with permission. My lease says I am not allowed to sublet my apartment without my landlord's prior written consent. You are entitled to request permission to sublet from the owner, and the owner may not unreasonably refuse such permission. Before setting up a sublease, the current tenant should seek written consent from their landlord. They almost always do not allow subletting without the landlords permission.