Change Those Locks... but wait... Bump Keys?

Real Estate Agent with RE/Max Associates DE#RA-0003085 PA#RS347136

I always recommend that my Buyer clients change the locks on the houses that they purchase after they own the home. You never know who had a copy of the key to the house, so if you want to have some increased peace of mind, change the lock.

Then I heard about bump keys and now I’m not so sure about that peace of mind. While bump keys have been around since the 1920s, they were more of a mainstay to locksmiths. With the increased sense of people being entitled to things that don’t belong to them, however, bump key usage by the general population is now on the rise.


What is a bump key?


Most cylinder locks have tumblers, in which metal pins need to rest at an exact height in order to open the lock. You insert your key, which tumbles the pins to the right height, and voila! You’re in. Bump keys have jagged teeth set really low so they fit into a lock tumbler. The jagged teeth of the key, when “bumped” by applying force and torque, make the pins in the tumbler bounce into the exact position needed to allow the lock to be opened.


There are numerous sites on the web that teach you how to make bump keys. Some of them have a small note that implores you not to use them to unlawfully anyone’s property, but with as easy as the information is to access, it’s good to prepare yourself, and your locks.


Great. So how do you stop that?


Pickbuster is one product advertised online that has mixed reviews. It’s a substance that you spray into the lock that supposedly won’t allow the pins to be bumped enough to engage the lock. Reviews of it don’t support its efficacy though.


Additional locking mechanisms, such as sidebars or sliders may thwart bumping. Additionally, locks with non-pin tumbler locking mechanisms stop bumping. Disc detainer, combination, wafer, warded, and level based locks are all immune to bumping.


The short story?


It’s still a great idea to change the locks on your new house but it would be even better to do some research before you rush out and buy the first lock that’s on sale.



Comments (48)

Sheila Anderson
Referral Group Incorporated - East Brunswick, NJ
The Real Estate Whisperer Who Listens 732-715-1133

Good morning Monica. They did a segment on this on Good Morning America yesterday. Scary stuff.

Jun 10, 2016 09:54 PM
Monica Hill

It was a segment on one of the news shows that got me searching for more information, Sheila. What also concerns me is that though we need to know what the burglars know, it probably also puts ideas out there for some nefarious minds who hadn't gone down that path yet. 

Jun 11, 2016 03:09 AM
Adana Bryant
Metro First Realty - Oklahoma City, OK

Thank you, Monica! Great info to pass along to my buyers. Adding more tools to the tool bag!

Jun 10, 2016 10:05 PM
Monica Hill

You're most welcome, Adana!

Jun 11, 2016 03:09 AM
Dana Basiliere
Rossi & Riina Real Estate - Williston, VT
Making deals "Happen"

In general... locks keep honest people out. By that I mean kids, teenage pranksters and the like. Robbers will break in the key word being "break".

Jun 10, 2016 10:46 PM
Monica Hill

True, Dana. Very true.

Jun 11, 2016 03:09 AM
Nina Hollander, Broker
Coldwell Banker Realty - Charlotte, NC
Your Greater Charlotte Realtor

Never heard of bump keys... and all I could think while I read your post was "geez, yet another thing to worry about!" Thanks for the heads up.

Jun 10, 2016 11:04 PM
Monica Hill

It's always something, Nina!

Jun 11, 2016 03:10 AM
Chuck Willman
Utah Homes - Alpine, UT
Utah Homes

Beyond bump keys there are several other inexpensive devices to open locks or spoof the garage door opener. There are means to open sliding doors and windows. If a thief wants to gain access they most likely will. I know- I've been one of those persons who has been broken into. That's why I suggest getting an alarm system. It's especially nice to have one that includes video. Sure- there's a monthly monitoring fee but it's worth it. 

Jun 10, 2016 11:39 PM
Monica Hill

I have clients who purchased a house with a video system that's accessed via the phone. Now they're wondering if the Sellers can still access it. Peace of mind is tough to find!

Jun 11, 2016 03:11 AM
Richie Alan Naggar
people first...then business Ran Right Realty - Riverside, CA
agent & author

To eliminate that nagging, doubting feeling, change the locks and be done with it

Jun 11, 2016 12:03 AM
Monica Hill


Jun 11, 2016 03:11 AM
John Dotson
Preferred Properties of Highlands, Inc. - Highlands, NC - Highlands, NC
The experience to get you to the other side!

WOW, never heard of such an item.

About 35 years ago my wife and I came home from the grocery store to find two burglars in our house - in the middle of the day.  There is a lot more to the story, but I can tell you, it is a life-altering experience.

 I guess if someone wants in, they will get in no matter what the technology.

Jun 11, 2016 01:24 AM
Monica Hill

True, John. Where there's a will, there's a way.

Jun 11, 2016 03:11 AM
Sham Reddy CRS
H E R Realty, Dayton, OH - Dayton, OH

Thanks for sharing:

Locking mechanisms, such as sidebars or sliders may thwart bumping. Additionally, locks with non-pin tumbler locking mechanisms stop bumping. Disc detainer, combination, wafer, warded, and level based locks are all immune to bumping.

Jun 11, 2016 02:53 AM
Monica Hill

I found that info, Sham, but I still welcome any who have more details or updates on this!

Jun 11, 2016 03:12 AM
Olga Simoncelli
Veritas Prime, LLC dba Veritas Prime Real Estate - New Fairfield, CT
CONSULTANT, Real Estate Services & Risk Management

Nice post Monica! I had no idea what a bump key was, let along how to deal with one.

Jun 11, 2016 03:10 AM
Monica Hill

Once I read about them, it struck me as.... Of course, they've existed for a while. Makes sense. Just upsets me that people take what doesn't belong to them. 

Jun 11, 2016 03:13 AM
Theresa Akin

The only time i advise my buyers of anything is to get the locks changed ASAP! Husband and I are considering this '" Looks like a doorbell when it's pushed and immediately lets the owner's know someone is at the door. Have seen some interesting video.  Truly lets you know if your neighbors look out for you more than they should. We have security cameras but this looks much more interesting. Don't remember the bump key but i'm sure my husband has.

Jun 11, 2016 08:16 AM
Monica Hill

Theresa, that's one I haven't heard of!

Jun 11, 2016 01:59 PM
Chuck Mixon
The Keyes Company - Cutler Bay, FL
Cutler Bay Specialist, GRI, CDPE, BPOR

As a licensed Locksmith I can tell you that Bump take a lot of practice to get to work. Locksmith tend to use lock picks for faster access. One of the lock I find very useful is the Kwickset Smartkey  that is very resistant to bumping and picking ( since there are NO pins) , but owner can change that key in 10 second.  All my rentals get rekeyed after every tenant  in 5 minute when i give the key to the new tenant.  If you have any question drop me a line. May even do a post in the near future on them.

Jun 11, 2016 12:32 PM
Monica Hill

Chuck, thanks SO much for weighing in! I saw reports in the media on these recently and hoped for some words of wisdom. Your blog post would be MOST welcomed! I will definitely drop you a line. Would love to have some printed info to give to clients!

Jun 11, 2016 01:57 PM
Praful Thakkar
LAER Realty Partners - Andover, MA
Andover, MA: Andover Luxury Homes For Sale

Monica Hill - wow! Bump Keys are scary (and thanks for sharing the details about it.)

Good advice for sure - get the new keys and additional latch mechanism to avoid someone entering the house unlawfully.

Jun 11, 2016 01:07 PM
Monica Hill

It's scary trying to keep up with all of the authentication details needed these days!

Jun 11, 2016 01:55 PM
Jan Green
Value Added Service, 602-620-2699 - Scottsdale, AZ
HomeSmart Elite Group, REALTOR®, EcoBroker, GREEN

I've told several people about these types of locks/keys.   I hope no one reads this that would try to open a home illegally!  Yikes!  It's great advice to get the right kind of secure locking system that makes people feel safe.  

Jun 11, 2016 01:59 PM
Monica Hill

I thought the same thing when I saw the reports on the media. Doesn't take much to give the wrong people ideas.

Jun 11, 2016 02:05 PM
Kay Van Kampen
RE/MAX Broker, RE/MAX - Springfield, MO
Realtor®, Springfield Mo Real Estate

I recently watched a locksmith in action using a bump key.  Not difficult at all to use........makes using just a door lock worthless!

Jun 12, 2016 09:56 AM
Monica Hill

It looked pretty easy to me, but then I won't be trying it myself!


Jun 12, 2016 01:41 PM
John Wiley
Fort Myers, FL
Lee County, FL, ECO Broker, GRI, SRES,GREEN,PSA

Thanks for your post Monica. I too, tell new home buyers to make a priority of changing locks.

I had not heard of bump keys, so I will have to research safer ways of locking the home.

Jun 12, 2016 09:23 PM
Monica Hill

Thanks, John. One of the things I love about the Rain is sharing timely information.

Jun 13, 2016 04:22 AM
Alicia Utz
EXIT Realty Associates - Lorton, VA
REALTOR & Military Relocation Professional in NOVA

Thanks for sharing -- I had not heard of bump keys.  Seems dishonest folks are always a step ahead.

Jun 12, 2016 10:24 PM
Monica Hill

So true, Alicia!

Jun 13, 2016 04:23 AM
Gene Riemenschneider
Home Point Real Estate - Brentwood, CA
Turning Houses into Homes

I suspect we will see more and more coded locks on homes.  Perhaps thumb prints to get in too.

Jun 16, 2016 03:46 AM
Monica Hill

I think you're right, Gene.

Jun 19, 2016 12:05 PM
Tara Mallane
Windermere Real Estate Sun Valley LLC - Ketchum, ID
Live where you play; love where you live!

I've never heard of a bump key, so thank you for teaching me something today!  I wonder how the new "smart" locks would fare with this?

Jun 16, 2016 07:57 AM
Monica Hill

Since posting this, I've started to gather suggestions about locks that can't be bumped. I'm not familiar with smart locks but I think I'm going to research them!

Jun 19, 2016 12:11 PM
Susan McCall - - Compass Realty Solutions
Compass Realty Solutions - Portland, OR
Listing and Buyer's Agent

Nothing can protect against a good strong kick.  And a determined burglar, like getting in through windows.

Jun 20, 2016 03:02 PM
Monica Hill

True. Where there's a will, there's a way. I just like to make my house, or my clients', the least likely target. 

Jun 28, 2016 12:17 AM
Bob Crane
Woodland Management Service / Woodland Real Estate, EXP - Stevens Point, WI
Forestland Experts! 715-204-9671

It is unfortunate that we have to deal with criminals everywhere we go.  I have installed cameras near my doors that activate when someone approaches the door and I can watch them from my phone.

Sep 05, 2016 03:14 PM
Monica Hill

Good plan, Bob! And yes, unfortunate that entire industries have emerged as a result of all of this.

Sep 13, 2016 01:48 PM