Signs you need a locksmith: sticking locks, worn keys and unknown key holders

Updated November 10, 2026 · KeystoneProGuide editorial team

Is a stiff or sticking lock a sign the lock is failing?

Sometimes, but often it is the door. ALOA, the locksmiths' trade association, lists five common causes of a lock that is hard to lock or unlock: the weather, poor door alignment, lack of lubrication, a worn or badly copied key, and a worn lock. Of those, it says poor alignment is the cause of most problems people call lock problems. Hinges wear and let the door drop a little, frames shift, and badly fitted weather stripping can push the door out of line, so the latch no longer meets the strike plate on the frame cleanly.

Two clues point to the door rather than the lock.

• It depends on the time of day. ALOA says humidity, temperature and direct sunlight can change how a door and lock behave, so a lock that works in the morning and binds in the afternoon is usually reacting to the door. It suggests booking a locksmith for the time of day the problem shows up.
• It is hard from both sides. ALOA says an alignment problem can make the lock difficult to work from inside and outside alike.

If the lock itself is the problem, wear is the usual reason. ALOA says every insertion and removal of a key wears the lock a little, and that the latch is especially prone to it. A worn lock may need rekeying, a new latch or full replacement.

When is the key the problem?

When it is old or a copy of a copy. ALOA says keys wear with age, and that duplicating an old or worn key can carry the wear into the new one. A fresh copy cut from an original key may fix it. If no good original exists, it says a locksmith may need to cut a new key from the lock's code.

When should you worry about who has keys?

Whenever you cannot account for them all. The clearest case is a move. ALOA says it is rare for every key to be handed over when a property changes owners, and that new houses in developments often have locks set up with construction keying for the builder's convenience, which it calls a security risk once the owner moves in. Police give the same advice: the King County Sheriff's Office in Washington State says to rekey or change all locks when moving into a new home, and Lower Moreland Township police in Montgomery County say the same for apartments.

Keys matter in burglaries too, though less than doors. In federal survey data for 2003 to 2007, residents who were home during an unlawful-entry burglary said in nearly four percent of cases that the offender had a key and used it. Lost keys, keys lent out and never returned, and spares hidden outside all raise the same question. The King County sheriff says burglars know to look under doormats and in planters.

When is a lock not enough for the door?

When it is only a knob lock. Lower Moreland police say a key-in-the-knob lock by itself is insufficient and that every exterior door should have a deadbolt, locked along with the knob whenever you leave. The King County sheriff recommends a deadbolt with a one-inch bolt and Grade 1 or Grade 2 locks on exterior doors.

The door and frame are part of the same system. The sheriff's office says even the strongest lock will not keep out a determined burglar if it is in a weak door, and recommends solid-core or metal doors at least 1 3/4 inches thick in frames of equal strength. The Bureau of Justice Statistics found that damaging or removing a door was the most common type of entry in forcible burglaries in that 2003 to 2007 data. A cracked frame, a loose strike plate or hinge pins that can be removed from outside are signs worth showing a locksmith; the sheriff says hinges should be inside or have non-removable pins. ALOA lists installing and repairing frames and doors among the services locksmiths provide.

Can a lock be a safety problem on the inside?

Yes. The National Fire Protection Association says a fire can leave as little as one or two minutes to get out once the smoke alarm sounds, and that when you walk through your escape plan you should check that doors and windows can be opened easily. A lock that sticks, needs a key from inside, or is blocked by a security bar without an emergency release is a sign to fix before it is needed.

What are the warning signs on a smart lock?

The same ones as any connected device. The Federal Trade Commission advises changing default passwords, using two-factor authentication where offered, updating firmware and apps, and disconnecting older devices whose security may be out of date. A smart lock that no longer gets updates, or one that still has the installer's default code, is due for attention.

What about car keys?

ALOA says a key fob that stops working most often has a dead battery, which you can usually replace yourself. The signs it gives for calling a locksmith are losing every key to the car, a key that worked before suddenly producing "bad key" or "no key" messages, a broken key, and a lockout. It says not to try to pull a key broken off in a car lock yourself, because that can ruin the lock.

What does a locksmith visit for these cost?

It depends on the job. HomeGuide, for example, lists lock repair or key extraction at $50 to $200 per lock in normal hours. The cost guide compares prices across four surveys, and whether to do it yourself or hire someone covers what you can safely try first. Local businesses are on the locksmiths directory page.

Sources

1. Common Lock Issues: Advice and Info, ALOA Security Professionals Association
2. Should I Change My Locks When I Move Into a House?, ALOA Security Professionals Association
3. Issues With Your Auto Key Fob, ALOA Security Professionals Association
4. What Services Does A Locksmith Provide?, ALOA Security Professionals Association
5. Doors and locks, King County Sheriff's Office
6. Prevent Burglaries with these tips from Chief Smith!, Lower Moreland Township Police Department
7. Victimization During Household Burglary (press release), Bureau of Justice Statistics
8. How to make a home fire escape plan, National Fire Protection Association
9. Securing Your Internet-Connected Devices at Home, Federal Trade Commission
10. How Much Does a Locksmith Cost?, HomeGuide