How to Change Locks When Roommate Moves Out

Your old roommate is out. Their key is probably in a jacket pocket, at a friend’s place, or “somewhere in their car.” Learning how to change the locks when a roommate moves out is one of those move-out tasks that sounds paranoid until you actually think about what an ex-roommate with your key could walk into on a random Tuesday.

Here’s the short version: get your landlord’s written OK first, use a licensed locksmith or a landlord-approved lock, keep the receipt, and hand a new key to the landlord. Everyone else on the current lease splits the cost.

Do I even need to change the locks?

Depends on how the roommate left. Three quick categories:

Amicable move-out, key returned, no drama: Rekeying is polite but not required. Do it if the person had access to your Amazon packages, spare cards, or anything that mattered.

Amicable move-out, key not returned: Change them. Cost is minor, peace of mind is real. You don’t want to explain to your renter’s insurance that you didn’t bother.

Bad move-out — fight, ghosting, unpaid rent, they took stuff, or you don’t fully trust them: Change them today. Don’t wait a week. The odds anything happens are low, but the cost of being wrong is your laptop, your stuff, or worse.

If your rental has smart locks, at minimum rotate the codes. Reset the guest access. Kick their profile from any app that controlled the door.

Am I allowed to change the locks?

Not without asking the landlord. This part trips people up.

In most states, the lease says the landlord must have working access to the unit at all times. If you swap the deadbolt without telling them and they show up for a repair the next month, you’re in breach. Some cities go further — you can only rekey through a locksmith the landlord approves.

The move is one email. “Hey, [old roommate] moved out and didn’t return their key. I’d like to rekey the front door for security. Can I use [locksmith] or would you prefer to arrange it? I’ll drop a copy of the new key at the office.”

Most landlords will say yes within a day. Some will just do it themselves and charge back the household. Either way, get the yes in writing before anyone touches the lock.

Who pays for the lock change?

Everyone currently on the lease splits it evenly. Not the person leaving. They left. The security is for the people who still live there.

Typical cost:

• Rekeying a standard deadbolt: $50 to $150
• Full lock replacement: $80 to $250 per door
• Smart lock install: $150 to $400
• Landlord-managed rekey with markup: $75 to $200

If the person who moved out did so under bad circumstances — didn’t pay their share, damaged the place — you can try to bill them for the lock change. Realistically, if they weren’t paying rent, they’re not paying for the locks. Consider it the cost of moving on.

If you’re mid-lease and need to figure out other move-out logistics, see our guide on how to find a replacement roommate.

What order do I do this in?

Quick sequence, do these in order:

1. Confirm they’re actually gone. Room cleared, mail forwarded, stuff moved.
2. Ask for the key back, in writing. Text is fine. This creates a record.
3. Email the landlord for approval to rekey.
4. Once approved, book the locksmith or go through the landlord.
5. Split the cost with current roommates, log it in whatever expense tracker you use.
6. Drop the new key at the landlord’s office. Get confirmation they received it.
7. If you have smart locks or a keypad, delete the old roommate’s code the same day.
8. Update Amazon package locker codes, gate codes, garage remotes — anything they had access to.

The whole thing should take a week, tops. Two hours of actual work spread across the week.

What if I can’t afford to change the locks right now?

Rekey just the deadbolt, not the whole lock. That’s the cheap version and it covers 90% of the risk. If a locksmith is out of budget entirely, most hardware stores sell rekeying kits for standard Kwikset or Schlage locks for around $15. You’ll need a YouTube tutorial and 20 minutes, but it works.

At minimum: change any keypad codes, and don’t leave a spare key hidden outside.

The one thing not to skip

Get the landlord’s yes in writing. That’s the whole game. Everything else is logistics. Skipping that step is how you accidentally end up with a lease violation on top of the roommate drama you were trying to end.

How homies handles this

homies. keeps move-out logistics organized — final bills, shared costs like lock changes, and who’s still on the lease — so the last three weeks of a roommate leaving don’t become a full-time job. Bill splitting, chore tracking, and AI mediation for the conversations that come up. rooming, minus the drama. Join the waitlist at joinhomies.app.