+421 Which country’s code? +421 Where is the code? Home › Forums › International codes › +421 Which country’s code? +421 Where is the code? This topic contains 0 replies, has 1 voice, and was last updated by yönetim 2 years, 3 months ago. Viewing 1 post (of 1 total) Author Posts 12/03/2019 at 03:01 #2174 yönetimKeymaster You must use the +421 code before your phone calls. The phone code for making international calls starting with +421 belongs to whom. +421 Slovakia If you dial your phone number by dialing this code, you can make your international call without error. Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic.