I understand that everyone with a rental villa has to submit a list of people staying with the Mossos. I've followed a link to their website https://www14.gencat.cat/mossos_hotels/AppJava/login.do but you obviously have to register to use it first.

Does anyone know how to register?
Thanks

To register a rental property you need to get a cedula first.  There is a technical architect in L'Ametlla who can do this. Then you take the cedula, house deeds and personal identification to the town hall to register the property.  Once the tourist registration number has come through you have to register with the Mossos. We did this at their police station in Tortosa. There is quite a bit of documentation to download, forms the holidaymakers have to complete when they arrive, notification of the tourist tax fees (to be displayed in the property) etc. Once the tourists have filled out the forms and paid their tax you have 24 hours to put the information on the mossos website.  Payment is made via the bank 4 times per year. Once the property has been registered all this info will be given to you, mostly in Catalan I'm afraid. It's quite a lengthy process but can be done 

Yes, we've registered at the Town Hall and paid our €50. We've received our HUTTE number. It's the process of registering our guests with the Mossos that has me foxed. I found to Mossos website but cannot see how to register as a user.

If they want people to comply with the rules, why do they have to make it so complicated? Maybe it's on purpose so they can fine us when we slip up?

Thanks for the reply. I was hoping to do it online.