Rekey vs. Replace Locks: Which Do You Need?

What rekeying actually does

Most residential locks are pin-tumbler locks. Inside the cylinder is a row of small spring-loaded pins of different lengths. Your key lifts each pin to exactly the right height so the cylinder can turn.

Rekeying means a locksmith removes the cylinder and replaces those pins with a new set matched to a new key. The lock body, finish and hardware stay exactly the same. The old keys simply stop working.

Rekeying is not the same as "changing the locks," even though people often use the phrases interchangeably. If your goal is to lock out old keys, rekeying usually does the job at a lower cost.

What replacing a lock does

Replacement swaps out the entire lockset or deadbolt for new hardware. You get a new lock body, new latch or bolt, new cylinder and new keys.

That makes sense when the hardware itself is the problem — or when you want something the current lock can't give you, like a keypad, a smart lock, or a stronger deadbolt.

When rekeying is the right choice

• You just moved in. Previous owners, contractors, neighbors and real estate agents may have keys. Rekeying is one of the first things to do in a new home.
• Keys are lost or stolen. Especially if anything with your address was with them.
• A roommate, partner or employee left and you aren't sure every key came back.
• You want one key for every door. If your locks share the same keyway (for example, all Kwikset or all Schlage), a locksmith can often rekey them to work with a single key.
• Rental turnover. Landlords and short-term rental hosts often rekey between tenants. See rental property lock changes.

When replacement makes more sense

• The lock is damaged. A cylinder that was forced, a bolt that drags, or a knob that's loose or broken. After a break-in, see break-in lock repair.
• The lock is worn out. Sticky, gritty or hard-to-turn locks are more likely to fail or snap a key.
• You want better security. Locks are rated by ANSI/BHMA as Grade 1, 2 or 3, with Grade 1 the most durable. Moving from a builder-grade lock to a sturdier deadbolt is a real upgrade. See home security lock upgrades.
• You want keyless entry. Keypad and smart locks can't be added by rekeying. See smart lock installation.
• Mismatched brands. If you want one key for the whole house but your locks use different keyways, replacing a few is sometimes necessary.

A few things people get wrong

How to decide in five minutes

1. Test every lock. Does each one turn smoothly and lock firmly? Smooth and solid → rekey candidate.
2. Look for damage. Pry marks, loose parts, a wobbly cylinder → replacement candidate.
3. Check the brand on the face. Note it for your locksmith; it determines whether locks can share one key.
4. Decide what you want. Same look, new key? Rekey. Keypad, smart lock or a stronger deadbolt? Replace.
5. Ask for both options. When you order a locksmith, describe each door. We'll confirm the price before any work begins.

What to expect during a rekey visit

For each door, the technician removes the cylinder, takes out the old pins, loads new pins cut to match a new key, and reinstalls the cylinder. Then every new key is tested in every lock. Before leaving, test the keys yourself, including on doors you don't use often like the garage entry or back patio.

Have all your current keys available if possible. It makes the job smoother, especially when keying several locks alike.

For businesses

The same logic applies to offices and storefronts, with a few extras. Businesses often need a master key system so managers can open every door while staff keys open only certain ones. When an employee leaves with a key, commercial rekeying is usually the quickest way to lock out the old key. Storefront aluminum doors often use narrow-stile deadlocks with a mortise cylinder, which can typically be rekeyed without replacing the lock body.