Written with people moving from Turkey in mind. The Portuguese rules still apply more broadly.
Registering Your Marriage
If you acquire Portuguese residency or citizenship, you must register your foreign marriage with the Civil Registry (IRN). This process, called "Averbamento," ensures your civil status is updated in the Portuguese system.
It is mandatory if you plan to apply for a spouse's residency or citizenship later. You will need your original marriage certificate, apostilled and translated, and the process can take several months to finalize.