With your valid residence permit you can travel to Spain.
You should take your recieved application confirmation (Poste Italiane SpA) with you.
From the authorities there should be no problems when returning, but some airlines act as if they have more to say in the matter than they in reality have.
Printing out the status the progress of the residence permit just before leaving may also be helpful.
Foreigners awaiting renewal of their residence permits can leave and re-enter Italy if they hold:
- the receipt issued by Italian Post offices (Poste Italiane SpA) certifying the submission of the application for renewal of their residence permit or EC residence permit for long-term residents;
- the expired residence permit;
- their passport or other equivalent travel document .
After submitting the application kit, the Post Office will give the applicant a special receiptstating that they have applied for the issue or renewal of their residence permit and a printout with their later appointment at the Police Headquarters. The applicant will find on the receipt a password and a user ID to check the progress of their residence permit issue on the official national website of the State Police. (Please, enter the file number - 10 characters - or the registered mail code -12 characters - relating to the application for your residence permit).