Anyone who has lived in a rented apartment in Japan long enough will eventually run into a key problem — a key that breaks, a key that goes missing, or a lock that simply refuses to turn. In every one of these situations, how quickly and correctly you respond matters. This article explains, from a property management perspective, who is responsible for paying to replace a lock, how to handle the most common key problems, and the correct steps to take when a key won't turn — including what not to do.
Who Pays to Replace the Lock When You Move Into a Rental?
As a general rule in Japan, the incoming tenant pays for the lock replacement carried out at move-in. This surprises many renters coming from countries where a landlord is expected to hand over a securely working lock at no extra charge. The Ministry of Land, Infrastructure, Transport and Tourism's guideline on restoration-related disputes actually states that it is more reasonable for the landlord to bear this cost, but the guideline is not legally binding — it is a set of recommendations, not a law — so if your lease specifies that the tenant is responsible, that clause takes precedence over the guideline.
- Some management companies do cover this cost, so it is worth confirming before you sign a lease
- Typical prices: about ¥15,000 for a disc-cylinder lock, roughly ¥25,000–¥30,000 for a dimple-key lock, and about ¥50,000–¥100,000 for a card-key system
The Most Common Key Problems in Rentals, and How to Handle Them Correctly
In day-to-day property management, the two most frequent key problems are a broken key or lock and a lost key. In both cases, trying to fix the problem yourself tends to backfire, and the first move should always be to contact your management company or landlord.
If Your Key or Lock Breaks
Squeezing oil into the keyhole or attempting other DIY fixes usually produces only a temporary improvement, and it can also mean the damage is no longer recognized as ordinary wear and tear — leaving you liable for the repair cost. Contact your management company right away instead of experimenting on your own.
If You Lose Your Key
- Contact your management company (use their 24-hour support line if it happens outside business hours)
- File a lost-property report at the nearest police box (kōban)
- If the key doesn't turn up, have the lock replaced — at the tenant's expense
Calling a locksmith to get back inside typically costs around ¥6,000. If you lost your driver's license or another form of ID along with your key, consider replacing the lock promptly to guard against the risk of someone using that information to get in.
Why You Should Never Replace a Rental Lock Without Permission
Swapping out the lock on a rented unit without authorization is a breach of your lease. The property, including its locks and keys, belongs to the landlord, not the tenant, so unilaterally changing it is treated the same as any other unauthorized alteration to the unit. If a landlord judges the act to have been done in bad faith, they can pursue you for damages. Any lock change, for whatever reason, requires the prior approval of your management company or landlord.
If you do want to change the lock yourself, three conditions generally need to be met:
- The replacement lock is compatible with the door
- You have the landlord's permission
- You have agreed in advance on what happens to the lock when you move out
Comparing Lock Types and Their Security Level
| Type | Approximate Replacement Cost | Security Level |
|---|---|---|
| Disc cylinder | About ¥15,000 | Low (discontinued in 2001) |
| Rotary disc (U9) | About ¥15,000 | Medium |
| Pin cylinder | About ¥15,000–¥20,000 | Medium |
| Dimple key | About ¥25,000–¥30,000 | High |
| Card key | About ¥50,000–¥100,000 | Highest |
What to Do — and What Never to Do — When a Key Won't Turn
A key that won't turn is usually caused by dirt buildup, wear, or, in winter, freezing inside the lock. Try the following steps, in order:
- Clean the key itself with a soft toothbrush
- Clean out the keyhole with a vacuum nozzle or a can of compressed air
- Apply lubricant made specifically for locks (or, in a pinch, graphite from a pencil)
- Try your spare key instead
- If nothing works, contact your management company and ask them to arrange a cylinder replacement
Things you should never do: pour water or hot water into the lock; use a lubricant not designed for locks (such as a general-purpose spray oil); force the key by turning it harder; attempt to pick the lock; or take the lock apart yourself.
Frequently Asked Questions
- Q. Does the incoming tenant always have to pay for the lock replacement at move-in?
- A. There is no legal requirement either way — it depends entirely on what your lease says — but in most cases the tenant ends up paying. Confirm this before you sign.
- Q. If I lose my key, who pays to replace the lock?
- A. If the loss resulted from the tenant's own carelessness, the tenant is responsible for the lock-replacement cost.
- Q. If a key won't turn, should I call a locksmith right away?
- A. Try cleaning it and applying lubricant first, and only contact your management company if that doesn't fix it. Replacing the cylinder yourself without permission is not allowed under a standard lease.
- Q. What if I lose my key late at night, when the management company is closed?
- A. Use the management company's 24-hour support line, or call a locksmith directly — a callout typically costs around ¥6,000.
