Green Man Gaming is indeed an approved reseller. There used to be an official list somewhere but all I've found is out-dated information. So I have taken the time to compile an up-to-date list with links to each approved reseller's webstore and detailing which exact form they sell PDX games in.
Currently the approved resellers (
updated 14/06/23) are:
If you still have doubts about a certain reseller not listed above, be sure to check this Support Article and if you're still not sure it is best to contact Support for advice:
https://support.paradoxplaza.com/hc...-Buying-keys-from-third-party-sellers-warning
NOTE that Paradox Interactive also sell Physical Copies of certain games (usually the flagship titles) under their own name on Amazon as well as the distributor "Ikaron". Both Sellers are officially viable ways of obtaining a physical copy of a Paradox Interactive game. When buying from Paradox Interactive on Amazon be sure to double check if it is a Direct Download or Physical Copy that you are purchasing in order to get your desired version of the game correct. Also worth pointing out that physical copies are only available to ship to certain EU countries including the UK.
Update (09/17): It is also worth pointing out that Paradox sell both Non-Steam and Steam required games from their Paradox Plaza store, you will receive both a Steam Key and a version of the game that is launched through the Paradox Launcher. You will receive two versions of the game at no extra cost. Please note that this does not mean you will receive two copies of the game, it is two versions of one license. This only relates to
Stellaris, Surviving Mars, BattleTech and
Tyranny at present but other PI games will be available on the Launcher as it is developed further.
Update (11/18): You can buy Paradox Products on the GOG store and activate the license keys through your Paradox account to have the games available to use on the Paradox Launcher. You cannot however use license keys bought on GOG to activate on Steam.
Update (09/19): Despite the discontinued partnership between Gamersgate UK and Paradox, by courtesy of Virtual Programming (licensed to publish) pre-2012 Paradox titles are available on the Gamersgate store including the later Victoria II exp. packs and are
solely available on MAC OS. These are all MAC-Direct Downloads.
Update (12/21): Instant-Gaming is
not an approved reseller.