How to duplicate keys

This guide is for neighbours throughout the area whose flat entrance doors were made by Kolnoa vrata and use Mul-T-Lock keys. Check your cylinder and key type before ordering, especially if the lock has since been replaced.

Illustration of a key, security card and flat entrance door

Where can you request a duplicate?

For a duplicate, contact the locking systems service:

Ilica 315, Zagreb

01 3750 777

Call before visiting

When calling, explain that you have a Mul-T-Lock key for a Kolnoa flat entrance door. Ask whether they can duplicate your specific key type, the price per copy, turnaround time and opening hours.

The address and phone number were supplied by the service in response to a duplication enquiry. No price, turnaround time or opening hours were given; confirm these directly with the service.

What should you bring?

Prepare an existing key and the original security card supplied with the keys. The card is used to control authorised duplication; ask about the specific requirements and any additional documents when calling.

The card may not show where to have a duplicate made. Keep it safe and bring it as instructed by the service.

If you do not have the card

Tell the service straight away and ask what authorisation or documents you need. Do not assume that the key alone is sufficient for a duplicate.

Which doors does this guide cover?

This guide concerns keys for individual flat entrance doors manufactured and installed by Kolnoa vrata, rather than keys for shared building entrances, garages or storage rooms. It is not limited to a single street number. If your flat has a different locking system, contact its manufacturer or an authorised service.

Sources and further information

Contact details and scope were updated on 7 October 2026.

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