A/S Københavns Telefonkiosker (old spelling: A/S Kjøbenhavns Telefonkiosker), often referred to as KTK, was an operator of staffed telephone kiosks in Copenhagen, Denmark. The first telephone kiosks were installed in 1896 to an Art Nouveau-influenced National Romantic design by Fritz Koch. A new and somewhat larger model was introduced in 1913 but Koch's original design was again used when a number of new telephone kiosks were installed in 1929.