Trading records rather than corporate existence: invoices, service agreements, payroll, tax returns and premises documents covering a continuous recent period.
Existence is registration; doing business is trade
Hypothetical example: A certificate of good standing proves a company exists. It says nothing about whether goods or services are being provided regularly, systematically and continuously, which is what the regulation requires of both entities. For a service company that installs and maintains milking equipment, the persuasive file is ordinary commercial paper: dated service agreements with named farms, invoices spread across months rather than clustered, payroll registers showing technicians paid, the lease on the shop and parts inventory, state and federal tax filings, and insurance certificates.
Twelve months of continuous evidence is more convincing than a large but single contract. If the American company slowed to almost nothing during a leadership gap, say so and show the recovery, because a reviewer who discovers the gap independently will treat the omission as the more serious fact. The same test applies to the Canadian company, which must keep trading after the transfer.