Decide that before anything moves. Government filing fees, legal work, translations, medical examinations and any sponsor administrative charge sit outside the invested capital, and a donor who has agreed to fund the investment may not have agreed to fund these. Write down who pays what, including the cost of responding to later evidence requests.
Take tax advice on both sides of the transfer
A gift of this size can have consequences for the donor, the recipient, or both, depending on where each is resident and how the funds are held. Ask qualified tax advisers in the relevant jurisdictions before the transfer rather than after, and keep their written analysis with the file. Also agree what happens financially if the investor withdraws before filing, since some professional fees will already have been earned.
Add one further question about the funds themselves: who bears the cost if a source has to be replaced. Where a donor's records prove unobtainable, or a portion of the gift cannot be documented, the investor may need a different source and the work already done on the first is written off. Establish in advance whether that is billed again, and whether a short preliminary review of the proposed sources can be bought separately before the main engagement begins.
Hypothetical example: an investor commissions a two-week review of the relative's records before instructing anyone on a self-storage development subscription, and that review identifies one period that cannot be evidenced, which is a far cheaper way to learn it than at exhibit eighty.