Do I need to add an area code to send a text message to a different place?

As long as texting between countries is normal, there is no need to add any number;

The landlord may wish to call the local China Mobile Customer Service 10086 or Unicom Customer Service 100 10 for further consultation and confirmation! The landlord can change hands and move the station according to the voice prompt!

Please accept my answer! Happy new year!