Collect relevant sending and receiving records, conversion details and any intermediary or charge information needed to follow the funds. Obtain the actual capital acknowledgment.
Connect the records without replacing the source history
Explain the lawful origin as well as the transfer mechanics. A receipt at the final account does not automatically resolve who owned the money or how it was acquired. Two separate accounts have to be assembled and they should not be fused into one narrative.
The first explains where the money came from and how it was lawfully acquired; the second explains how it travelled. A file that is strong on mechanics and thin on origin is the more common shape, because transfer records arrive of their own accord while source records have to be sought out — tax filings, sale agreements, records of an estate or a business distribution, whatever the actual history requires. Assemble the source evidence first, since it is older, held by more parties and slower to obtain.
While waiting for it, keep the transfer documentation in the order the transfers happened, with the amount and currency at each step, and note in the file which questions remain open instead of closing them with an assumption. One test of whether the origin account is finished: it should answer how the money was earned or received, not merely which account held it immediately beforehand.