After closing. The qualifying relationship must exist when the petition is filed, so a petition submitted on the strength of a signed but unclosed deal describes a relationship that does not yet exist.
The closing date is the earliest filing date
Sequence the transaction first. The relationship is created by the completed transfer of ownership, and USCIS will ask for evidence that it exists at filing, so the share register must already show the new owner. Between signing and closing, use the time to gather everything else: the manager’s payroll history for the continuous year, the organizational chart of the U.S.
plant as it will be under new ownership, and the evidence that the plant is doing business. Once closed, file promptly; if the plant has been operating for more than a year under the seller it is not a new office, and the initial period requested can be up to three years. If the deal converts the plant into a new legal entity that has not yet begun operations, expect the one-year new-office limit and the requirement to show premises and capacity.
Both companies must stay active throughout, and the seven-year cap means an extension calendar should start on approval day. A first review produces a closing-to-filing checklist: completed ownership transfer, foreign payroll proof, U.S. operating evidence, and a duty chart.
Hypothetical example: a greenhouse-benchmarking company acquires a U.S. analytics firm but plans to delay changing the share ledger until month end. The signed ledger, not a press release, settles control on filing day.
File after the legal records match the transaction, then calendar extensions against the maximum stay.