Legal subletting: getting landlord approval
Start with the lease clause. If it requires consent, make a written request with the proposed subtenant’s name, dates, space, and any required application information. Ask the landlord to state any missing documents or decision in writing.
Do not mistake acceptance of rent from someone else for permission. State law and lease terms can treat approval, notice, and waiver differently. An unapproved sublet can create risk for the original tenant and the person moving in.
If consent is refused, do not improvise. Ask the Rent Board or a tenant lawyer how the local rules apply to your lease and occupancy change. The answer may differ for a replacement roommate, a temporary subtenant, and a full lease assignment.
Sources: SF Rent Board guidance, California Civil Code.