The Short Version
"Jointly and severally liable" is standard contract language that shows up in almost every multi-tenant lease. Broken apart: "joint" liability means you're all responsible together, and "several" liability means each of you is also responsible individually for the entire obligation, not just a proportional slice of it. Put together, it means the landlord can choose to collect the full rent — or the full cost of damage — from any one signer, from a few of you, or from all of you, in whatever combination gets them paid.
Why Landlords Use This Language
Without it, a landlord might only be able to collect each roommate's "share" of the rent from that person individually, which is harder to enforce if one roommate disappears, has no money, or is hard to locate. Joint and several liability puts that risk on the roommates to sort out amongst themselves instead of on the landlord. This is also the default under ordinary contract law even without special lease language: when several people jointly promise a single payment and all benefited from it, that promise is generally presumed joint and several unless the contract says otherwise (Cal. Civ. Code § 1659), and a promise made in the singular but signed by more than one person is presumed joint and several too (Cal. Civ. Code § 1660). A written lease clause spelling this out just makes explicit what the law often assumes anyway — but always read your own lease rather than assume, since wording varies.
What This Looks Like in Practice
Say three roommates sign a lease for $3,000 a month rent, split evenly at $1,000 each. If one roommate stops paying, the landlord isn't limited to chasing that one person for their $1,000 — they can demand the full $3,000 from either of the other two, or split the demand however they choose. The remaining roommates are on the hook for the whole amount to the landlord, even though they each only agreed to pay a third between themselves.
This also applies to damage. If the unit is damaged beyond normal wear and tear at move-out, the landlord generally doesn't have to figure out which roommate caused it — they can deduct the full repair cost from the shared security deposit, or bill any or all of the signers for it.
Between Roommates, It's a Different Story
Joint and several liability describes what the landlord can do to you — it doesn't erase what your roommates owe you if you end up covering their share. If you pay more than your portion because a roommate didn't pay, you generally have a separate claim against that roommate to get reimbursed, though pursuing it usually means small claims court rather than anything your landlord is involved in. A written roommate agreement that spells out each person's share, and what happens if someone falls behind, makes that conversation much easier if it ever comes up — it won't change what the landlord can demand, but it gives you something to enforce against your roommate directly.
What to Check Before You Sign With Roommates
Confirm everyone who's actually living there is named on the lease — an unlisted roommate has no formal standing with the landlord, and you may be the only one legally on the hook for their share. Ask whether the security deposit is refunded as one lump sum to all signers or split automatically, since that's often where roommate disputes actually surface. And talk through, in writing, what happens if someone needs to leave early or stops paying, before it happens rather than after.
If a Roommate Needs to Leave the Lease
Being jointly and severally liable doesn't end automatically just because a roommate moves out or you all agree among yourselves that they're done paying. As far as the landlord is concerned, everyone who signed the original lease generally stays on the hook until the landlord formally agrees otherwise — usually through a lease amendment, a new lease that drops the departing roommate's name, or a written release. If your roommate is moving out and you want them off the hook (or you want to make sure you're not still covering their share after they leave), get that change in writing from the landlord specifically, not just as an agreement between roommates. See what happens if my roommate moves out before the lease ends for what that process usually looks like.
Honestkey™ reads an uploaded lease and tells you plainly whether it names you as jointly and severally liable, so you know what you're actually on the hook for before a roommate situation goes sideways.