Crime For Members

The secret language used by burglars to break into homes in Spain 

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The secret language used by burglars to break into homes in Spain 
Make sure you keep your eyes open for some of the tricks and markings burglars use which we've listed in this article. (Photo by JAVIER SORIANO / AFP)

With the latest news that criminals in Valencia have been marking locks with lip balm to later burgle the homes, we review the letters, symbols and other tricks used by thieves to pinpoint which properties are fit for break-ins. 


Spanish police have for some years been warning homeowners and their neighbours to keep a close eye out for odd markings on doors in apartment blocks or residential areas, because there's a high chance they're there for a reason. 

The latest proof of this is the arrest of two men in Valencia on November 16th, after police caught them in the act of breaking and entering properties which their gang had earlier marked as 'suitable' with a very discreet clue: lip balm on the lock. They would then use a thin sheet of plastic to open the doors, a method known as el resbalón in Spanish.  

In the first half of 2023, there were just under 60,000 burglaries reported in Spain


With the mass exodus of millions of Spaniards to the coast over the summer period, this is typically the time when most break-ins take place, especially in places in Spain’s interior that go quiet while many of their inhabitants are on holiday elsewhere.

For several years, there have been reports in the Spanish press that organised crime gangs are operating differently to what most people would expect from burglars. 

An increasing number of their members are posing as ‘tourists’ on holiday in Spain, taking time off work in their home countries to ransack empty chalets in upmarket Spanish neighbourhoods. Those who work as locksmiths, plumbers or who have handymen jobs are being hired by these crime networks for their skills with the draw of earning ‘an extra salary’ while on vacation, Spain’s National Police has reported.


“They’re from many different countries” and rarely carry weapons on them as their intention is to carry out the burglary and escape unnoticed.  

Authorities also report a rise in the number of women joining these gangs. "No one expects that a woman with a shopping bag or trolley will be involved in a burglary,” Domingo Medina, representative of Spain’s Civil Guard Association (AEGC) told 20 minutos. 

READ ALSO: How to prevent a burglary at your home in Spain

Madrid’s Civil Guard unit is now seeking to inform the general public of the warning signs that a burglary in their neighbourhood could be about to happen. 

One of the most common tricks used by burglars to identify properties that are suitable for breaking into involves placing a small piece of transparent plastic in the door frame. 

If after a few days the slim plastic sheet is still in the same place, that tells them that nobody has opened the door during that time and therefore there’s a higher chance that they can break in unnoticed.

Then there are a number of symbols and letters gangs use to inform their members of which properties can be burglarised, along with other information. 


According to Spain’s Civil Guard, neighbours should look out for the following symbols and letters on door frames, walls, locks, gates and other areas near the property’s entrance:  

  • A small triangle indicates the property has been burglarised before. 
  • Numbers inside circles indicate the property will be vacant that month. Usually the number refers to the month (ie. 7 would mean empty in July).
  • The letter X means the owners are on holiday. 
  • A diamond shape points out that the dwelling is unoccupied. ​
  • The letter W specifies that the property is suitable for a burglary at night. 
  • ​The letter M indicates that the property is empty in the morning. 
  • The letter D tells burglars that the property is empty on Sundays.

The following image posted by Spanish locksmiths AG Cerrajería gives an even more detailed breakdown of some of the imagery used by burglars, including some alarming symbols to indicate “disabled person”, “woman on her own”, "children alone in the afternoon" or “elderly person”. 

symbols burglars spain


As can be seen, the symbolism is in some cases different to that reported by Spanish authorities.

They recommend that tenants, property owners or neighbours who spot something like this which looks out of the ordinary first take a photo of it, contact the police by calling 091 and then ask if it would be possible to rub or clean it off.

Another trick Spain’s national police has informed the general public of this summer is similar to that of the small piece of plastic, but in this case involves a string of silicone glue going from the frame to the door. Again, if it remains unbroken for a number of days it indicates that the door has not been opened by the property’s owners or tenants.

Make sure you keep your eyes open for some of the tricks and markings burglars use which we've listed above.

Spain is generally a very safe country where violent crime remains uncommon, but non-violent forms of theft are far more prevalent. 




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