What does 'they have received no kingdom as yet' mean in Revelation 17:12?
It means the ten kings or leaders do not yet possess the power and political clout the Antichrist will have. They later receive authority as kings for a short time alongside the beast, then agree with one mind to surrender their power and strength to him.
Les explains that the ten horns are ten kings, presidents, or prime ministers. They have received no kingdom as yet because they do not have the power and political clout that the Antichrist will have. But they receive power as kings for one hour—a short period—with the beast, or Antichrist and his empire. They all agree, have one mind, and give their power and strength to the Antichrist. He has been maneuvering and will come with peace, prosperity, and flatteries, not civil war.
And the ten horns which thou sawest are ten kings, which have received no kingdom as yet; but receive power as kings one hour with the beast.