IMI payments

After successfully paying our IMI through our bank for two years, the finance department has stopped sending us bills  with a payment code.
We have signed up to the portaldasfinances , but under outstanding payments, it says nothing is owed, despite not having paid anything for two years.
An entire day spent in the financial office in Lisbon only referred us to the portal.
We want to pay.
Has anyone any advise.

I don't understand your second sentence: "despite not having paid anything for two years" which contradicts the first sentence which said you've been paying your IMI for two years?

If you have not paid IMI on your home in Portugal as of yet, it's likely you've qualified for an exemption as a new home owner. Three-year exemptions are common for IMI.

https://www.idealista.pt/en/news/financ … ng-imi-tax