Best Practices for Lock Rekeying
Lock rekeying is one of the most cost-effective security measures a property owner can take, allowing the internal pin configuration of an existing lock cylinder to be changed so that old keys no longer work. Unlike a full lock replacement, rekeying preserves the existing hardware while rendering previously issued keys useless — a critical distinction when keys have been lost, a tenant has moved out, or a property has changed hands. Understanding the correct procedures, risks, and professional standards behind rekeying helps owners make informed decisions and avoid common mistakes that can compromise security or damage hardware.
Best Practices for Lock Rekeying Overview
Rekeying a lock involves disassembling the cylinder, removing the existing driver and key pins, and replacing them with a new pin stack that corresponds to a freshly cut key. The process requires the correct pinning kit for the specific lock brand, a plug follower, a key gauge, and precise attention to pin height tolerances. When done correctly, the cylinder is reassembled to factory specification and operates as smoothly as it did before service.
The core principle behind professional rekeying guidelines is that the procedure must not degrade the lock’s original security rating. A Grade 1 commercial lock should still meet ANSI/BHMA Grade 1 standards after rekeying. A residential deadbolt should retain its pick resistance and key control properties. Any deviation — over-pinned chambers, incorrect spring tension, or improperly seated retaining clips — reduces the effective security of the lock even if the door appears to function normally.
Rekeying standards also require accurate record-keeping. For property managers or facilities teams overseeing multiple units, maintaining a log that tracks which cylinders were rekeyed, when, and which key codes were assigned is essential. This documentation supports audits, reduces liability, and provides a clear chain of custody for access credentials.
Key Factors in Rekeying Procedures
Brand compatibility is the first factor any technician must verify. Lock manufacturers use proprietary pin sizes, keyways, and cylinder tolerances. Kwikset hardware, Schlage, Medeco, Mul-T-Lock hardware, and Baldwin each require brand-specific pinning kits. Using generic or cross-brand pins introduces dimensional inconsistencies that can cause binding, false sets, or premature wear on the shear line. Technicians following sound rekeying techniques always confirm the lock brand, model, and keyway before opening a pinning kit.
Key control is another central factor. High-security cylinders from manufacturers like Medeco or Abloy locks use patented keyways and restricted key blanks, meaning new keys can only be cut by authorized dealers. When rekeying these cylinders, the technician must document the new bitting code and ensure replacement keys are ordered through the correct channel. Rekeying a restricted-keyway cylinder with a standard blank defeats the purpose of the key control system entirely.
The condition of the existing cylinder matters as well. A worn or damaged cylinder should be assessed before rekeying. Signs of wear include a loose or wobbly plug, scoring on the shear line from pick attempts, or corrosion on internal components. Rekeying a compromised cylinder without addressing the underlying damage produces a lock that accepts the new key but remains vulnerable. In these cases, cylinder replacement — or full lock replacement — is the appropriate recommendation, not rekeying.
Masterkey systems add a layer of complexity to rekeying procedures. In a master-keyed environment, each cylinder must accept both the master key and the individual change key. Pinning must account for master wafers placed at specific depths within the cylinder stack. Errors in master-wafer placement can allow unintended cross-keying, where a change key from one unit inadvertently operates a cylinder in another. Technicians managing masterkey systems should use dedicated software or pinning charts to verify each chamber before final assembly.
Costs and Risks
The cost of professional rekeying is generally lower than full lock replacement because the existing hardware is retained. For a standard residential deadbolt, the average cost reflects labor and a small parts cost for the new pin stack. Average: $25–$50 per cylinder · Range: $20–$75 · Travel: free in service area. Commercial cylinders with restricted keyways or masterkey requirements carry higher labor costs due to the additional pinning complexity.
DIY rekeying kits are available for popular consumer-grade locks, and while they can work for straightforward single-cylinder deadbolts when instructions are followed carefully, they carry real risks. The most common error is incorrect pin sequencing — placing pins in the wrong order or at the wrong depth — which produces a cylinder that either fails to operate or operates with reduced resistance against picking. A second common error is improper use of the plug follower, which can cause the driver pins and springs to scatter inside the lock body, requiring a full disassembly and often damaging the housing.
There is also the risk of voiding a manufacturer’s warranty. Many lock warranties specify that internal modifications must be performed by a certified locksmith. A rekeying error that damages the cylinder may not be covered if the manufacturer determines the work was done improperly. For higher-end locks where replacement cylinders are expensive, this is a meaningful financial risk.
Security risk is the most serious concern. A lock that appears to work after an amateur rekeying attempt may have subtle flaws — a mis-seated spring, a pin that rides slightly above the shear line — that reduce pick resistance or cause intermittent failure. In a residential context, a deadbolt that occasionally fails to fully extend because of an internal pin issue creates a security gap that may go unnoticed for weeks. Professional rekeying includes a post-service function test and, in most cases, a brief inspection of the lock’s overall condition.
When to Call a Locksmith
Certain scenarios make professional service the clear choice. Moving into a new residence or commercial space is one of the most common. The number of copies made from the previous owner’s or tenant’s keys is unknown, and rekeying all entry cylinders on move-in day closes that gap immediately. A locksmith can rekey all locks to a single key in the same visit, simplifying access without requiring new hardware.
After a break-in or attempted break-in, a locksmith should assess whether rekeying is sufficient or whether the lock itself has been compromised. Forced entry often damages the cylinder, strike plate, or door frame in ways that rekeying alone cannot address. A professional inspection will identify whether the security failure was related to the lock’s pin mechanism or to the hardware and installation around it.
Employee turnover in a commercial setting is another standard trigger for professional rekeying. When a key-holding employee departs — particularly under adverse circumstances — the affected cylinders should be rekeyed promptly. In facilities with access control systems, this process may also involve deactivating electronic credentials, but for mechanically keyed cylinders, rekeying is the direct equivalent of credential revocation.
High-security or masterkey systems should always be handled by a qualified locksmith. The pinning tolerances in restricted-keyway cylinders are tighter than in standard residential hardware, and masterkey matrix errors can create security vulnerabilities across an entire property. The cost of professional service in these contexts is modest compared to the exposure created by a pinning error.
Recommended Next Steps
Before scheduling a rekeying service, property owners should take stock of every keyed entry point: front door, back door, garage entry, storage units, and any secondary access points. Providing the locksmith with a complete list in advance allows for efficient scheduling and ensures no cylinder is overlooked. It also gives the technician the opportunity to flag any cylinders that may need replacement rather than rekeying based on age or condition.
If the goal is to simplify key management, ask about keying-alike — the process of configuring multiple locks to operate on the same key. A locksmith can rekey several cylinders to a single bitting during one visit, reducing the number of keys on a ring without replacing any hardware. This is particularly useful in residential settings where separate exterior doors currently require different keys.
For commercial properties or landlords managing multiple units, consider whether the current access architecture is appropriate. A masterkey system allows a single master key to operate all cylinders while each unit retains its own individual change key. If the property already has a masterkey system, verify that the rekeying is performed within the existing matrix rather than outside it — a technician unfamiliar with the system may inadvertently break the masterkey hierarchy.
After rekeying is complete, test every cylinder with both the new key and any secondary keys before the technician leaves the property. Confirm that old keys no longer operate the lock. Request documentation of the key codes assigned to each cylinder, and store that information securely. For restricted keyways, note the authorized dealer or manufacturer contact required for future key duplication. These steps take only a few minutes but establish a clear record that supports ongoing security management.
Related coverage: Common Problems With How to Rekey a Lock Safely.
Call Low Rate Locksmith
Low Rate Locksmith provides professional rekeying services for residential and commercial properties, available 24 hours a day, seven days a week, across the US and Canada. Whether the job involves a single front-door deadbolt, a full property rekey on move-in day, or a complex masterkey system, trained technicians carry brand-specific pinning kits and perform post-service function tests on every cylinder. To schedule service or get a same-day appointment, call (833) 439-8636.