I recently got engaged and want to open a combined checking account between myself and my partner. I understand that there might be a gift tax trigger, but I don't really understand when/if this will occur? What other tax consequences do I need to consider?

I simply want to have a joint checking account that we can each have our salaries directly deposited into and pay expenses from. Does it matter if one of us makes more than the other? Also what would happen if i transferred money from the joint account into a separate joint checking (or brokerage) account? Both accounts would be under the same bank (Schwabb), I just want it to be easy for us to deposit money into and transfer any leftover into savings (brokerage account).