The tax office has detected 17,000 cases of income received by landlords that has not been declared.
According to data from the Fiscal Affairs Secretariat of State, between 2011 and 2014 a total of €200 million in rental income was not declared to the IRS.
This could lead to a bonus of €60 million in overdue taxes payable to the State by landlords.
The discrepancy was detected easily by cross-referencing tax returns from tenants with income declarations submitted by landlords.
The president of the Lisbon Owners Association, Luis Menezes, said that cases of tax evasion are an exception.
"We are convinced that most landlords comply with their tax obligations. Certainly there will be cases where this is not the case, but we are talking about a sector that, in the context of housing and commerce, has millions of signed leases. In this context, the number in percentage terms is not high," said Leitão.
Landlords will be notified by the Tax Authority to correct the situation voluntarily but they will be subject to fines for any proven infringements.
