Those "id" names are really confusing; I assume they are all shorthand for "acct_id", or... maybe not. I think account_credit & account_debit need foreign keys

Those "id" names are really confusing; I assume they are all shorthand for "acct_id", or... maybe not. I think account_credit & account_debit need foreign keys back to billing_account, and they probably are gonna need their own primary columns eventually (so you can add on addl metadata like 3rd party transaction tracking). I'm not sure what billing_rate's relationship is to billing_account, if any...