how i check details for my NIF number

Your name will appear in the top left corner on the screen, next to your NIF:

https://www.acesso.gov.pt/v2/loginForm? … /dashboard

(Select tab NIF)

You can check your contact details (phone and email) here:

https://sitfiscal.portaldasfinancas.gov … osPessoais

Personal details:

https://www.portaldasfinancas.gov.pt/pt … on?pai=660

Your rental contracts:

https://imoveis.portaldasfinancas.gov.pt/arrendamento/

(...)

@Antony Gamal Abdelmalak

Try this

https://www.nif.pt/

Also it useful to know that you can check details for various alojamente locals at

https://rnt.turismodeportugal.pt/RNT/HomePage.aspx

I mentioning this because the level of dishonesty that I have encountered in the Portoguese real estate market is unusual.

I also reccomend that you check your netbank in Portugual, and see if they offer an insurance that protects you in any conflict with landlords. These insurances are usual here. I have seen it in several netbanks. If such offers exists, there must be a market.

You have no obligation to inform anyone of what sort insurances you have. They might be insulted, or something. In my native country nobody raises an eyebrow if you mention insurances. A mundane thing.

@Antony Gamal Abdelmalak
Try this
https://www.nif.pt/

.....
-@MickeyWy

For individuals (which is the case of Antony), this link only serves to check if a NIF is valid or not. Personal details like name and address, are (obviously) private and are not showed. For companies, it is useful because you can validate the NIF of a company, name and address of that company (public information that can be shared).