The shift codes so far and a little note about golden keys
The first shift code was hidden at different points in the Mask of Mayhem teaser trailer and it's: C35TB-WS6ST-TXBRK-TTTJT-JJH6H - Community Day skin for Salvador and 5 golden keys
The second one was revealed in the Borderlands 3 official trailer at PAX East and it's: C3W33-RZ6ZJ-TFJ6C-TTJ33-RFHX5 - 100 (yes one hundred!!!) golden keys
The third one so far was released in the Official Borderlands Discord Server and is: 53KBB-KXXRC-RZ66Z-WFJBB-WSRZ3 - Community Day skin for Zer0 and 5 golden keys.
All the codes are only for Borderlands 2 but you can use them on any platform (if you play on an Xbox you have to have Xbox Live Gold to redeem shift codes). I'm not sure if or when these expire.
Now, a note about golden keys. You can only have up to 255 golden keys in your account’s active balance (the balance that shows up in game) at once so if you have say 155 keys or more in your account and redeeming the second code would put you over 255, all of those keys will be put into your reserve. It won’t put some in your active balance and then put the remainder in your reserve. So don't be alarmed if you don't see the keys in your account. Those keys will only become available for your to use once you have space in your active balance for all of them. Then all 100 will be added at once. I’m not sure if that reserve has a capacity though.
I'll continue to update this list as more shift codes come out
