Dividends from my Norwegian AS to Portugal — 25% or 15% withholding?

Without doing anything: 25% Norwegian withholding. Under the treaty: capped at 15% for individuals — and just 5% for a Portuguese company holding at least 10% of the AS for 12 months. The reduction must be claimed with documented treaty residency, and refund processes for over-withheld years are slow but real. On the Portuguese side, the dividend is taxed by your regime (IFICI can exempt it; standard rules tax it with credit for the Norwegian withholding). Sequencing distributions around your move date is where the real money is.