to be clear - you need a tax rep to obtain your initial NIF if you are non-EU.
This usually comes with a 1-year contract of tax representation.
However, the requirement to maintain your tax rep were relaxed back in 2022, and are described in detail in this thread:
Moreover, note that any Portuguese citizen resident in Portugal can serve as your tax rep. One of my friends was happy to help me out by serving as my tax rep and saving me a few bucks. Drinks are on me.
For a typical non-resident, the tax repās obligations are negligible. Once a year he receives my property tax bill and hands it over to me when convenient, but I can also download this online, and my IMI bill is set for autopay from my Multibanco account anyway. Heās not on the hook to pay my taxes.
Dear All,
We bought the house 2 years ago. No news from GV yet still waiting the pre approval. The house is not rented so we dont have any income. So can you help me to understand IMI Tax? Last year they said that we dont have to pay. But i think second year we should pay it? We have tax rep. and just paid the representative fees last year. I dont have password i cant check it but i was thinking why we didnt paid last year.
Thank you
IMI is for Property Tax and is completely separate from income tax (rental income if applicable).
When you finally get your password youād find yourself in tax arrears on IMI and your tax situation being ānĆ£o regularizadaā, meaning that you would not pass your biometric appointment.
So yes, I suggest you get your access to the Portal das Financas sorted as the next step, and then pay your IMI+whatever fines are due.
And in case youāre wondering āwhatās this guy talking about, I told him already I donāt have password!..ā then hereās the link below. Look for ārecuperar senhaā.
Thank you 
Also they said, when i get rental income i have to fill electronic income receipt from portuguase tax web site. And the rent will cut %25 every month not yearly?