All Bills for raising Revenue shall originate in the House of Representatives; but the Senate may propose or concur with Amendments as on other Bills.
This explained:
According to the Article One, Section Seven of the United States Constitution (the Origination Clause), "All Bills for raising Revenue shall originate in the House of Representatives; but the Senate may propose or concur with Amendments as on other Bills".
A bill may originate in any of the two chambers of Congress, except bills of law for raising revenue, which according to the Constitution may originate only in the House of Representatives. The House has claimed that in the same way it can itself create bills of allocation, but the Senate is opposed to this demand.