Contemporary operating records for each: financial statements, tax filings, payroll, customer contracts, licences and premises. The standard is the regular, systematic and continuous provision of goods or services, not the mere existence of an office or agent.
Operating, not merely incorporated
The doing-business requirement catches groups out in two directions. On the Canadian side, a company that has wound down operations while its people work abroad can fail it, which matters because the qualifying organization must continue to operate throughout the transfer. On the American side, an entity incorporated some time ago but never traded is not doing business simply because it has an age and a bank account.
The evidence expected is ordinary commercial material: statements showing revenue, payroll registers, signed customer or supplier contracts, business licences, a lease or title for premises, and insurance. For a newly acquired operating business, the closing documents plus the first months of trading records are the natural proof that the enterprise continues under the new ownership.