Correct. At least in the US, “regulation D” restricts you from using your savings account as your “transactional” aka checking account. A long time ago before

Correct. At least in the US, “regulation D” restricts you from using your savings account as your “transactional” aka checking account. A long time ago before that was a thing and interest rates were non zero, my local credit union had automatic overdraft protection that drew from your savings account with no fees. So I would just keep the checking account balance at zero and draw from my savings for every check. Apparently at some point this triggered some automated check and I could no longer do this. Regulation D only allows you to transfer money from your savings account to checking six times per month, but apparently that rule was suspended during COVID.