The advice here does not apply to anyone covered by the Withdrawal agreement (British only), see the brexit pages for what’s relevant to you.
If you are a non-EU national and plan to come to Italy for a period exceeding three months, you must apply for a residence permit.
If it is your first time in Italy, you have 8 days to apply for a residence permit.
To obtain the issue of a residence permit you need:
- The application form;
- Your valid passport or any other equivalent travel document bearing an entry visa, if required;
- A photocopy of your passport or another valid travel document bearing an entry visa, if required;
- 4 recent and identical passport-size photographs;
- A €14.62 electronic revenue stamp;
- Documents supporting your request for the type of residence permit you are applying for.
If you are already in Italy and your residence permit is close to its expiry date, you must apply for renewal at least:
- 90 days before expiry date if your residence permit is valid for 2 years;
- 60 days before expiry date if your residence permit is valid for 1 year;
- 30 days before expiry date in all other cases.
The validity of your residence permit is the same as that indicated on your visa, i.e.:
- Up to 6 months for seasonal work or up to 9 months for seasonal work in the specific sectors requiring this extension;
- Up to 1 year if you are attending a duly documented course of study or a vocational training course;
- Up to 2 years for self-employment, open-ended employment and family reunification.
If you are planning to come to Italy for short visits, business, tourism or study for a period not exceeding 3 months you are not required to apply for a residence permit.
https://www.poliziadistato.it/articolo/10716