Changing the locks and securing a rented home after you move in

Key rules

• Permission: Get your landlord's consent in writing before changing the cylinder.
• Cost: Agree who pays before you buy; no rule fixes it.
• Cylinder: Buy a certified high-security cylinder, not a cheap one.
• Old cylinder: Keep the old cylinder in case you must restore it when you leave.

Change the cylinder on day one, but ask first

You can secure your new home by swapping the lock cylinder (the bombín) on the day you move in. Before you buy anything, check two things: your landlord agrees in writing, and you both know who pays.

Previous tenants, agents and the owner may all hold copies of the old keys. A new cylinder is the quickest way to end that.

Check permission first

Read your contract for any clause on locks or works in the home. Some contracts forbid changes or say what you must restore when you leave.

Changing a cylinder is not normally a structural work, so landlords usually accept it. Still, ask. Send a message or email so you have it in writing. If you change it without telling the landlord, it could count as a breach if your contract forbids it.

Agree these points in the same message:

• You will give the landlord a copy of the new key, if you both want that.
• You will keep the old cylinder, so you can put it back when you leave if the contract requires it.

Your landlord cannot enter your home without your consent, even with a copy of the key. Access is allowed only in limited cases.

Who pays

No rule fixes this, so agree it before you buy.

• If the lock is faulty or worn, the landlord pays.
• A move-in change for security is usually negotiated. The landlord pays or you split it, though many tenants pay themselves.
• If a break-in damaged the lock and it was not your fault, the landlord's building insurance or your contents insurance may cover it.
• If you lost the keys, you pay.

Your contract can set this differently, so check it.

Choose the right cylinder

Cheap cylinders are easy to bump, drill or snap. Buy a certified high-security cylinder with anti-bumping, anti-drill, anti-pick and anti-snap features. Check the grades on the box or datasheet. Look for EN 1303 certification, with high grades for key security and attack resistance. Brands with patent-protected keys stop copies being cut without authorisation.

A good cylinder costs roughly 40 to 150 euros, plus fitting.

Measure the old cylinder first. Take the total length, then each side from the fixing screw, in millimetres. A result like 30/30 is common. A wrong size leaves the cylinder sticking out or loose.

Fit it

• Do it yourself: you pay only for the cylinder, about 30 to 120 euros. Remove the central screw, turn the key slightly and slide the old cylinder out. Fit the new one in the same way.
• Hire a locksmith (cerrajero): this is safer if the lock is unusual. Expect roughly 60 to 150 euros including the part. Emergency and night call-outs cost more.

The new cylinder should not stick out past the door plate, because a protruding one is easier to snap. Fit a security escutcheon (escudo) over it.

Control the keys

Count the keys you receive and note the number. Keep the owner card safe. With a patented or card-controlled system, only an authorised dealer who sees the card can cut copies.

The checklist below gives the steps in order. The FAQ covers cost, ratings and what happens if you skip asking.

Checklist

• Ask your landlord for written consent to change the cylinder (bombín), by message or email.

• Agree with your landlord who pays for the new cylinder before you buy it.

• Measure the existing cylinder: total length and each side from the fixing screw, in mm, for example 30/30.

• Change the cylinder the same day, or hire a locksmith if the lock is unusual.

• Check that the new cylinder does not protrude beyond the door plate, and fit a security escutcheon (escudo) over it.

• Count and note the keys you receive, and keep the owner card safe, since only an authorised dealer showing it can copy the keys.

• Give the landlord a copy of the new key if you agreed to.

Frequently asked questions

Who pays when I change the lock cylinder at move-in?

There is no fixed rule, so who pays at move-in is usually agreed with the landlord. Landlords often pay or split the cost, though many tenants pay. If the lock is faulty or worn, the landlord pays; if you lose keys, you pay.

How much does a good anti-bumping cylinder cost?

A good certified cylinder costs roughly 40 to 150 euros, plus fitting. A locksmith (cerrajero) usually charges roughly 60 to 150 euros including the part, and more for night or emergency calls. Fitting it yourself costs only the cylinder.

What happens if I change the cylinder without telling my landlord?

It could count as a breach of your lease if the contract forbids it. Changing a cylinder is not normally structural work and is often tolerated, but the landlord cannot enter without your consent either way. Keep the old cylinder to refit when you leave.

What cylinder ratings should I look for on the box?

Look for EN 1303 certification, with top grades of 5 or 6 for key security and attack resistance. Also look for anti-bumping, anti-drill, anti-pick and anti-snap features. The cylinder should not stick out beyond the door plate.