The original invoice or purchase agreement, proof of the outbound transfer, the vendor's credit note or cancellation notice with its reason, the incoming refund entry, and the replacement agreement with the new payment. Add correspondence showing the commercial reason. Together these turn an unexplained credit into an ordinary business event.
Ask the vendor while the file is open
Request the credit note and revised agreement while the vendor can still identify the transaction readily. If a wire reference is missing, ask the bank for a confirmation naming both parties. Keep immigration-preparation invoices separate from business expenditure in the schedule, because the two are analysed differently and the treatment of each item deserves a real look.
A statement showing a balance is not enough: the file needs the lawful original source and the path into the enterprise. Use genuine agreements, orders and payments that establish the actual commercial arrangement. Ask for three years of business tax returns, payroll summaries showing how many people are employed and whether they will stay, and the state licence with the name of the current qualifier. The first review should flag any unexplained deposit or unsigned agreement. Put the answers in the E-2 file next to the purchase agreement, and make any outstanding reissue a condition of closing, not a hope.