What kind of proof of application for residence regularisation is required for my NISS application?

Social Security requires proof of application for residence regularisation as part of the NISS application process. This helps them assess your application before granting NISS.

You need to provide either of the following:

• Portuguese Visa Stamp + Proof of Application for Portugal National Visa
  • A photo of your passport showing the Portuguese visa stamp, along with the completed application form you submitted at VFS.

• AIMA Confirmation Letter
  • Document confirming that your residence permit has been granted. This is given to you after you successfully complete your AIMA appointment.

Source: Atribuição de Número de Identificação de Segurança Social (NISS)