Revenue bills have to start in the House. The Senate may make propose amendments, just like any other bill.
In general when there are differences, it used to go to a conference committee to work things out.
Not sure what the reality is these days.
Reality is just exactly what either/both Speaker of the House and Senate Majority Leader deem it to be.
Exactly as the Queen of Hearts in Alice in Wonderland.
(Sorry for the sour mood...the Storm must be at its peak right now.)