Mul-T-Lock is a high-security brand you will find on a lot of New York apartment doors, usually as the cylinder on a deadbolt, a surface-mounted rim lock or a mortise lock. When a key goes missing, or you move into a place that already has one on the door, the question is the same as with any lock: who else has a key? Rekeying answers it. The lock stays on the door, and only the new keys will open it.
How it differs from a standard lock
A standard pin-tumbler cylinder has a single row of pins. A Mul-T-Lock uses telescopic pins, a pin inside a pin, and newer platforms such as Interactive+ and MT5+ add further elements to the key and cylinder. Rekeying one takes the correct parts for that platform and a technician who knows it, because the pins are not interchangeable with ordinary locks.
In practice, the cylinder comes out of the lock, its pins are changed to match a new key, and it goes back in. Each new key is tried in the door before the job is finished.
When to rekey
- You moved in, and previous tenants, owners or contractors may still have keys.
- A key was lost or stolen, especially together with something that shows your address.
- A roommate, employee or cleaner who had a key no longer needs one.
- You want several doors to work with one key. Cylinders on the same platform can often be keyed alike when they are rekeyed together.
Rekey or replace the cylinder
Rekeying makes sense when the cylinder is in good shape and does what you need. Replacing it is the better call when it was damaged in a break-in attempt, when it is badly worn, or when you want a newer platform than the one on the door. Either way, the old keys stop working and you get a new set. For doors that need more than new keys, see high-security lock installation.
Renting? Check before you change anything
New York's Multiple Dwelling Law lets tenants add their own lock to an apartment entrance door (no more than three inches in circumference), as long as the landlord gets a duplicate key on request. Changing the cylinder the building installed is a different matter, so check your lease or ask management first. In a co-op or condo, the building may also want a key on file for emergencies.
What to have ready
- A working key, if you have one. It makes the job simpler.
- The key card that came with the lock, if you still have it. It identifies the key system.
- A photo of the lock from the outside and one of the edge of the door, so we can see the cylinder and the lock body.
- How many keys you need, and who should have them.
We work from our storefront at 130 7th Ave S in Greenwich Village and take service calls across all five boroughs, plus nearby Nassau County and Westchester. Call (917) 495-1990 or text us those photos so we can suggest whether a rekey or a new cylinder fits your situation. A recent Mul-T-Lock deadbolt installation is on Our Work.