game pass online key for Xbox series S

If the key works, then the game should work on the Xbox Series S

It's important to know which game your friend bought.

I say this because there are currently three versions of the Series X/S game. Gta 5 Online, Gta 5 Series X/S and Grand Theft Auto V (Xbox One and Xbox Series X|S).

If he has purchased Grand Theft Auto V (Xbox One and Xbox Series X|S), which gives access to the game for Xbox One and Xbox Series S/X, he can play online with you as long as he downloads the Xbox One version, so you and he will have the same save and can play online.

If he is a Game Pass Ultimate subscriber he can download the game in the Xbox One version and play with you.

Perfect! Thanks!

Just to make sure - I can have my Xbox One as my Home console so it is sharing Game Pass on that.

If I sign into the Series S console (on my own) family members will still be able to play online / Game Pass downloaded games on the Xbox One and I can use Series S with Game Pass, etc. as well.

Have I got that right?

Do you mean an Xbox One S or an Xbox Series S? The game is not available for the One.

The game plays the same with or without Game Pass. You would just need Gold if you wanted to play online multiplayer.

Game Pass Core is just an online subscription, so if you purchase Game Pass for Xbox, you do not lose Game Pass Core, you will have both subscriptions at the same time. If you cancel Game Pass Core, then you will lose your Xbox One/Series X|S Games with Gold Games.