The sender pays and the provider collects and remits quarterly
What the document says“The remittance transfer provider with respect to any remittance transfer shall collect the amount of the tax imposed under subsection (a) with respect to such transfer from the sender and remit such tax quarterly to the Secretary”
The section requires the sender to pay the tax, requires the remittance transfer provider to collect it from the sender and hand it to the Secretary quarterly at the time and in the manner the Secretary provides, and makes the provider liable for any tax not collected when the transfer is made.
What the document actually says“The remittance transfer provider with respect to any remittance transfer shall collect the amount of the tax imposed under subsection (a) with respect to such transfer from the sender and remit such tax quarterly to the Secretary”
The firm sending the money must collect the tax. It takes it from the sender. It must hand it over every three months.
The sender owes the tax in the first place. If the firm fails to collect it, the firm owes it. That is a backstop, not a choice.
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