Rekey
Updated November 6, 2026
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Safety
Rekeying is generally a low-risk service, but a few precautions matter. Never attempt to disassemble a lock cylinder while a door is the only barrier to an occupied building, and avoid forcing a key that will not turn, since broken keys and damaged pins turn a simple rekey into a full replacement. For automotive work, keep the vehicle parked and off unless a technician advises otherwise, because a partial car ignition rekey can leave a vehicle unable to start. If a lock shows signs of tampering, drilling, or a break-in attempt, treat the door as unsecured and do not rely on it overnight.
Before the visit
A little preparation speeds up any rekey visit. Count the doors, knobs, deadbolts, and cylinders that need new keys, including garage side doors and exterior car door locks. Gather any working keys, since matching the keyway helps confirm the lock brand and model. Decide whether every cylinder should share one new key or use separate keys per entry. For a rekey smart lock, have the admin code or app access available. For auto rekey work, keep the vehicle registration or proof of ownership handy, as technicians verify ownership before servicing car locks or ignitions.
Repair vs replace
A rekey is often the repair itself, but related issues can be fixed rather than replaced. If a lock cylinder turns roughly, sticks, or needs jiggle, a cleaning and pin reconfiguration during a door lock rekey frequently restores smooth operation. Worn tailpieces, loose strike plates, and misaligned latches can usually be adjusted on the spot. A rekey car door lock works well when the lock mechanism still turns freely but the key is lost or the old key was copied too many times. Ignition cylinders that accept a new key but feel gritty can often be serviced during a car ignition rekey rather than swapped out.
When to replace
Replacement makes more sense when hardware is beyond a pin change. Severely corroded cylinders, locks with cracked housings, deadbolts with stripped screws pulling out of the frame, and knob sets with broken internal springs usually need new units instead of a rekey. If a lock brand is discontinued and replacement key pins are unavailable, a technician may recommend new hardware. For vehicles, an ignition that will not turn at all, or one with a snapped key lodged inside, often requires cylinder replacement rather than a simple car ignition rekey. Upgrading from old knob locks to modern deadbolts is another common reason to replace during a home rekey visit.
Common issues
| Symptom | Likely causes | Safe check | Stop when |
|---|---|---|---|
| Old keys should no longer open a door after moving in or a roommate moving out | Strangers or previous occupants may still hold copies of the original key | Inspect the key for unknown copies and count how many people might still have one | Someone attempts to enter with an old key, or the lock shows signs of tampering |
| A house key turns with grinding or needs wiggling to lock the deadbolt | Worn pins, dirt buildup inside the cylinder, or a misaligned bolt | Try a second working key and apply graphite lubricant, avoiding oil-based sprays | The key breaks off, or the cylinder spins freely without engaging the bolt |
| A car key was lost and the vehicle door or ignition needs to stop accepting it | A missing key that could be found or copied by whoever retrieves it | Confirm the vehicle is locked and parked in a secure location; locate proof of ownership | The ignition will not turn at all or a key fragment is stuck inside the cylinder |
| A rekey smart lock is needed after a tenant change or a lost phone with app access | Digital codes and app credentials may still be active for former users | Review the manufacturer app for active user codes before removing power or batteries | The lock becomes unresponsive, repeatedly beeps, or fails to accept the admin code |
| A door knob spins loosely or the latch no longer catches when the door closes | Worn internal springs, a damaged spindle, or a latch bolt failure inside the knob set | Test the latch by pressing it with a screwdriver while turning the knob gently | The knob detaches, or the door cannot be secured at all before a technician arrives |
| A lock cylinder rekey is wanted so one new key works across all exterior doors | Multiple mismatched lock brands or keys accumulated over the years | Check each lock face for brand stamps and confirm each cylinder still turns with its current key | Any cylinder is rusted shut, has a stripped mounting screw, or cannot be turned for removal |