(Updating this post as some more keys have just appeared.) 10 x keys for the original game, although there's a comment below suggesting it may not be as universal as reported. Otherwise, the BL3 code should work for all platforms, including Switch. Unlikely any more keys will be released, but if they are and you come across them feel free to post in the comments or create your own deal. Enjoy!
Another round of keys for Borderlands, the original game this time. I’m not including Switch in the title as I don’t think it’s been released for that platform yet. Otherwise, they're 'universal' so will still work on PC, Xbox, and PlayStation. If more keys are released later this weekend I'll update the post with the code(s).
Borderlands 3, 3 keys:
Borderlands 1, 5 keys each:
You don't need to own the game to redeem them. These are not codes to unlock the game, they're only for receiving special loot in-game. They can be redeemed in-game or through your SHiFT Account online(shift.gearboxsoftware.com) (membership is free).