SolvedDT14506 | Double Taxation Relief Manual: Norway: interest and royalties
From HM Revenue & Customs · Double Taxation Relief Manual
Interest and royalties arising in Norway and beneficially owned by a resident of the United Kingdom are not taxable in Norway.
The reduced rate provided by the treaty is not given if the interest or royalty is effectively connected (see INTM153110 eighth sub-paragraph) with a permanent establishment which the United Kingdom resident recipient has in Norway.