Section 5-12-120 of Chicago's RLTO requires landlords to accept a reasonable sublessee and cap a departing tenant's liability at the gap between the old rent and fair rental — if the replacement tenant pays the same or more, that gap is zero. The protections don't apply to owner-occupied buildings of six units or fewer.

A Chicago renter who needs out of a lease mid-term — a job transfer, a health change — routinely hears some version of the same landlord claim: you owe rent until I find someone. What the city's Residential Landlord and Tenant Ordinance says is more precise, and the arithmetic cuts differently than most tenants expect.

Section 5-12-120 of the RLTO imposes two obligations on landlords when a tenant terminates a lease early. First, the landlord must make a good-faith effort to re-rent the unit "at a fair rental, which shall be the rent charged for comparable dwelling units in the premises or in the same neighborhood." Second, the landlord must "accept a reasonable sublease proposed by the tenant without an assessment of additional fees or charges." A reasonable sublessee is one who clears the same objective screening criteria the landlord applies to everyone else — income verification, credit, rental history.

The liability formula follows from those duties. If the landlord re-rents at fair rental, the original tenant owes only the amount by which the original rent exceeds what the landlord subsequently collects. If the replacement tenant pays the same rate or more, that differential is zero — the departing tenant owes nothing on the rent gap. Advertising costs can be recovered, but only if the landlord made a genuine effort to re-rent and documented it.

One exemption matters. The RLTO's subletting protections do not cover owner-occupied buildings with six or fewer units — that carve-out is in Section 5-12-020(a). In those properties, a no-sublease clause in a lease is enforceable, and a landlord can decline any proposed sublessee.

Two ordinances now in City Council committee — Mayor Brandon Johnson's Protecting Renters Ordinance and the competing aldermanic FAIR proposal — concentrate on just-cause eviction and relocation assistance. Neither addresses the subletting formula or the mitigation duty under § 5-12-120.

Tenants with subletting or early-termination disputes can reach the Metropolitan Tenants Organization's free hotline at 773-292-4988, weekdays 1 to 5 p.m.