How to Change Commercial Door Lock: Step-by-Step Replacement Guide
Published Date: Aug 27, 2025
Worn-out hardware, a recent tenant turnover, or updated security needs can all be good reasons to change a commercial door lock. Whether you're looking to upgrade old components or take better control over access, learning how to replace a commercial door lock can help you handle the task with more confidence. In this guide, Sure Lock & Key walks you through a simple approach to commercial door lock replacement, covering the tools you’ll need, what to expect during the process, and when it might be time to call in a professional.
When and Why You Might Need Office Door Lock Replacement
Security needs change over time — particularly in workplaces with frequent staff changes, visitors, or shifting access policies. Whether an employee didn’t return their key or the hardware just isn’t working the way it used to, commercial door lock replacement is a smart move in many situations.
Here are a few common reasons to consider it:
- Lost or unreturned keys
- An outdated or malfunctioning lock
- Upgrading to more secure hardware
- Changing tenants or personnel
- Meeting new security guidelines or compliance standards
If the key sticks, the latch doesn’t catch, or the lock simply feels off, it might be time for a full replacement. This not only restores function — it helps you stay in control of who has access to your space.
What You’ll Need to Change a Commercial Door Lock
Most lock replacements only require a few tools:
- A screwdriver (usually Phillips or flathead)
- A compatible replacement lockset
- A tape measure (to confirm spacing and dimensions)
- Optional: a drill (if any screws are stripped or stubborn)
Knowing the lock type helps, too. Cylindrical locks are common on interior commercial doors and are typically easier to install. Mortise locks, found on entry doors, are more complex and may take extra care during removal and reinstallation.
If you’re only replacing the internal mechanism and not the full assembly, check out our full guide on how to change a door lock cylinder.
How to Replace a Commercial Door Lock: Step-by-Step Instructions
Whether you’re doing the job yourself or explaining it to a building maintenance team, here’s a simplified process:
- Remove the existing lock: Unscrew the faceplates from both sides. If it’s a mortise lock, remove the screws from the door’s edge and gently slide out the body. Keep all parts organized.
- Take accurate measurements: Measure the backset (distance from the door edge to the lock hole center) and screw spacing. This ensures a clean fit for the new hardware.
- Install the new lock: Insert the new latch or lock body, align the components, and fasten with the supplied screws. Check that the lock sits flush and level with the door.
- Test the operation: Lock and unlock the door a few times. The latch should move freely. Adjust the alignment if needed.
These steps typically take 15–60 minutes, depending on the lock style and door condition. If anything feels off during the process, professional support may save you time and stress.
Sure Lock & Key: Here for Your Office Security
Some situations are ideal for DIY, but others call for a trained hand. Smart locks, keypads, electronic access systems, and older doors with custom cutouts can make things more complicated. If your business has strict building codes or advanced security requirements, calling in a commercial locksmith can prevent costly mistakes.
Sure Lock & Key is a family-owned company with over 35 years of experience handling everything from basic commercial door lock replacement to high-security lock systems. We serve businesses across Connecticut, New York, Rhode Island, Illinois, Florida, Texas, Alabama, and Arizona. Learn more about our commercial locksmith services to see how we can support your business today.