Depending on the case, you are indeed going to pay less than 5%.
I know︅ someone who has gone through the process some months ago, I'll explain.
As an example:︆
TAXES
You make €100,000 in a year
90% (€90,000) is exempt
For governmental purposes, 90%︇ of your income doesn't exist.
The government considers you have earned €10K in one year.︈
Therefore, your tax rate is 23%.
You will have to pay €2,300 in Income Tax.︉
Effectively, you have paid 2.3% of your income in taxes.
SOCIAL SECURITY
Case 1:
Regardless if you're going to be self-employed, or under contract, if you’ve paid regular social security︊ contributions in another EU country for two full years before going to Italy (e.g. to︋ look for a job), you’re entitled to social security cover for a limited period from︌ the date of the last contribution made in your home country and you will not︍ have to make any contributions during that period of time. You’re also entitled to be︎ covered by the national health service.
Case 2:
If you are going to be under️ contract, and you make, for instance, €100,000 in one year, as we've said, the government will consider your actual income to be €10,000, therefore, the social security rate applied to you is 9.19% on the total income (€10,000), this means you will have to pay €919
Case 3:
If you are self-employed, the rate varies depending on your profession, nonetheless, the contribution will still be very low considering only 10% of your income will be taken into account.
TOTAL
Case 1:
€100,000 Income
- 90% (€90,000) EXEMPT
= €10,000 Taxable
23% Tax (€2,300)
+ 0% Social Security
YOU GET: €97,700
YOU PAY: 2.3% (2,300)
Case 2:
€100,000 Income
- 90% (€90,000) EXEMPT
= €10,000 Taxable
23% Tax (€2,300)
+ 9.19%︀ Social Security (919)
YOU GET: €96,781
YOU PAY: 3.2% (€3,219)
Case 3:
Similar to Case︁ 2