Before signing anything unconditional. The question depends on the seller's records and on a growth plan, and both take time to obtain and write. A purchase agreement should leave room to walk away if the records do not support the plan.
Diligence first, deposit second
Sequence the transaction so the information arrives before the commitment does. Sign a conditional agreement, obtain the records, have them reviewed, write the plan, and only then move to an unconditional commitment. Sellers often push for speed, and a broker's timetable is not the buyer's. Where the immigration application depends on the same records, the review serves both purposes and the effort is not duplicated. If the seller will not allow a conditional structure, that constraint should be weighed as a risk rather than accepted as market practice. Money that has been irrevocably committed is, by design, difficult to recover, and that is precisely why the diligence belongs before the commitment rather than after it.
Hypothetical example: Viktor, a microbrewery founder, wants to pay suppliers before the purchase contract explains what happens if entry is refused. He should negotiate the commercial commitment first, using clear escrow or contingency language that binds the transaction while addressing visa refusal in a legally acceptable way. The signed contract and transfer trail must show that funds are genuinely committed and at risk rather than freely recallable. Ownership, treaty nationality, substantiality, operating readiness and non-marginality should be reviewed before the payment date. A rushed supplier payment cannot replace those elements, while an entirely refundable reservation may fail to show that a real investment has moved beyond intention.