The point at which a clearly qualifying period of employment is complete within the relevant preceding window, together with how quickly the supporting records can be assembled. If the contracting years cannot be counted, that date may be considerably later than the length of the working relationship suggests.
Give the employer the honest date
A manager who has worked with the person for years will assume the transfer can happen immediately. Explain early that the counting question may push the date out, so the business can arrange cover rather than discover the gap late. Approval, any visa step, admission and the start of lawful work are separate stages that follow the qualifying date rather than replace it.
Hypothetical example: a specialist in the organisation's grain-handling control systems is expected on site for a commissioning window six weeks away, and the manager has assumed his long involvement settles the history question. A first review would establish the date the qualifying period completes before any other preparation begins, and would tell the operating team that date in the same week. Where the date falls after the commissioning window, the business can arrange cover or reschedule; discovering it a fortnight beforehand leaves it with neither option and a case that still cannot be filed.