That is a commercial term for the consulting agreement. Consult the USCIS schedule for Form I-129 charges and CBP for any port-of-entry charge. Agree professional fees and travel reimbursement in writing before the engagement starts.
Put the immigration costs into the agreement as a line item
Hypothetical example: her corporation's standard agreement covers fees and expenses but says nothing about immigration. Add a clause stating who pays to prepare the TN package, whether any CBP port-of-entry charge or USCIS Form I-129 charge is reimbursed, what happens if admission is refused and the engagement cannot proceed, and whether any preparation cost is recoverable if the distributor cancels early. If the distributor files Form I-129, verify its charges on the USCIS schedule; premium processing, where available, is an additional amount. Beyond immigration, price the ten months honestly: travel between branches, accommodation, U.S. tax withholding on fees paid to a Canadian corporation, and the accountant's cost of handling cross-border tax on both sides. None of these affect eligibility, but a consultant surprised by withholding halfway through an engagement is distracted from the work that justifies the status. Keep receipts separately for immigration and for the engagement.
Hypothetical example: an occupational therapist receives a twelve-month U.S. offer and discovers that the employer expects her to pay every filing and licensing expense. The signed offer and the reimbursement policy settle the commercial point before either side spends money. Price two pathways: a request at a port of entry, or an employer-filed Form I-129, including any professional advice needed for each. She must not treat TN as a way to open her own therapy business; its work must be for the U.S. engager described in the application.