How the Spanish tax authorities communicate with taxpayers?
Normally, they would send a communication via postal mail to the address they have in their records. For this reason, it is important to file Form 030 in order to communicate the tax and notification address. In addition, you can have access online to notification registering in Cl@ve PIN.
Could I inform as a tax address my company address?
No, the address that would be your preferred correspondence address for AEAT in future should be at your home in Spain (if you’ve already found one), or a family/friend house that would receive notifications and could let you know. You should not use an address from your company, as the Spanish tax authorities only accept a personal address.