How long should a Callander marina group allow between an acquisition and an L-1A filing?

Long enough for the corporate paperwork to be complete and for the American entity's trading position to be clear. Filing immediately after closing often means the relationship evidence is unfinished and the acquired business looks like a new office, which brings a one-year initial approval instead of three.

Two clocks run at once, and they are not synchronized

The first clock is the beneficiary's: one continuous year of qualifying employment abroad must fall within the three years immediately preceding the petition, so a long-serving manager has flexibility, while someone recently promoted may not. The second clock belongs to the American entity. If it has been doing business for less than one year at the time of filing, new-office rules apply and the initial approval runs for one year, with an extension requiring evidence that the operation has developed as described.

An acquired going concern with continuous trading history is usually in a stronger position, but the acquisition must have closed and the ownership must be recorded. The sensible order is to complete the corporate documentation, confirm the American operation's trading record, then file, rather than to file and assemble evidence while a request for evidence is pending. Where the acquisition itself is still being negotiated, the filing timetable belongs inside that negotiation, since closing dates are far easier to shape before signature than afterwards.