Getting guests through the security gate

We have friends arriving at our apartment after we leave.  Is there a letter that people give to their guests to get them through the security gate?  When you rent out your apartments what paperwork do you send to your guests?  If anyone has the wording for a letter that works to get them through with minimal fuss that would be great.  I know they will need to show their passports and we will advise security of their arrival but just want to make sure it is a smooth operation for them.

Any help would be appreciated from seasoned renters. 

Hi

I sent an email to the below providing details of the visitors, date, time etc including the apartment details and they forwarded it onto the security gate.

Condado de Alhama condado@mileniun-levante.es

Jane

Many thanks Jane - that's great!

Hi Claire,

      Have pm'd you

Thanks Chris and Tracey - I've sent you a reply - feel free to pop in for a drink!

I normally also include map and directions and emergency contact info. Also it's a good idea to remind guests about checking the enter property on arrival and contact owner in case of any problem.

  'checking the enter property on arrival and contact owner in case of any problem'

Great advice.

 wtf does this mean?