My company has no Norwegian entity — do I still have to run payroll in Norway?

Yes, if your employees work in Norway. Foreign employers without a Norwegian entity can use the PAYE simplified tax scheme (skatteordning for utenlandske arbeidstakere): the employer deducts a flat 25% withholding (or 17.4% if the worker holds an A1 certificate keeping social security abroad) and reports monthly via a-melding. The worker gets no tax return — the deduction is the final tax. You still need an employer registration in Enhetsregisteret, you still file a-melding every month, and construction workers still need HMS cards before the first day on site. PAYE does not remove employer obligations — it simplifies the tax calculation only.