Is there an IMI exemption for people buying a home?
Yes. An own permanent home can get a temporary IMI exemption of up to 3 years, subject to rateable-value and income limits. It is not automatic.
In this guide
There is relief, but it is temporary
If the property is your own permanent home, you may qualify for an IMI exemption of up to 3 years, extendable by 2 more in certain cases. It depends on limits of rateable value (VPT) and household income.
It is not automatic
The exemption depends on meeting the Tax Authority's requirements. It is worth confirming whether your case fits the conditions in force at the time of purchase.
What makes it lapse
The exemption lapses if you put the property to a different use within six years of purchase (other than selling it), or if you do not make it your own permanent home within six months of buying.
Worked example
For a property with a yearly IMI of €500, a 3-year exemption is worth about €1,500 saved over that period — more where it is extended. (Example figures.)
Sources

Susana Vasconcelos
- Intermediária de crédito autorizada pelo Banco de Portugal n.º 0008496
- Mais de 10 anos na banca