Dry run - nothing is persisted. Legs are credited in order: sell (proceeds at the card's latest valuation reduce principal and the card leaves the collateral base), pay (reduces principal), add (a card on file for the borrower joins the collateral base). closedBySell + closedByPay + closedByAdd = closedAmount. Sale proceeds and the payment count only for the part the loan's own repayment allocation puts on principal - worked out by a dry run of the loan's transaction processor that saves nothing; the rest is reported as appliedToDueAmount. On some loans that includes scheduled interest or fees on the installments the payment prepays, not just amounts due today. payment.method and the template fields do not change the arithmetic. A plan that cannot be priced in full is rejected rather than priced in part, and sale proceeds above the loan's total outstanding are a 400 with the same error submit returns. An earlier cure plan's payment still processing does not fail the preview; it is reported as paymentInProcessing. Requires READ_COLLATERAL.