As soon as the ownership records reflect the purchase and the U.S. business can be shown to be trading. There is no waiting period, but assembling the corporate and employment evidence normally takes several weeks, and USCIS processing follows.
Let the corporate records catch up before anyone drafts the petition
The sequence runs closing, records, evidence, petition, decision, travel, and skipping a step invites a request for evidence rather than saving time. Immediately after closing, the corporate secretary should update the register and issue certificates for the U.S. entity, and the group's registers should be brought current on the Canadian side as well.
In parallel the two operating companies can produce their employment letters and payroll extracts, and the acquired business can pull payroll, customer invoices and its lease or deed. A file built this way is often ready within a few weeks. Bertrand should not begin managing the U.S.
operation in any capacity that amounts to employment until the petition is approved and he has been admitted. Extensions are filed before the current period ends, and the seven-year ceiling applies from the first admission.