Owners renting out tourist accommodation must submit the Modelo 30 tax form via the Portal das Finanças. Deadlines depend on payment dates—for example, income received on February 22 must be reported by April 30. Supporting documents for tax benefits must be retained for 10 years and may be requested by the tax authority. The form includes eight sections: the first five cover basic details, sections six and seven report monthly financial totals, and section eight provides information on non-residents, including tax IDs, income, and applicable withholding rates. Material taken from https://t.me/s/lepta