will DLCs work both new and used?

I want to buy assassins creed odyssey, shadow of the tomb raider, farcry 5, skyrim, but not sure if the dlc for each will work. Can anyone tell me if the special edition for each will work used it do I have to buy them new? Also I do not have internet access to my console atm so the dlc can't be downloaded.

If you buy used from Gamestop then you won't get the DLC. Buy them new and you'll get the DLC voucher.

If the DLC codes have been used by the previous owner, then no they won't work.