The official process calls for identity, eligibility, and funding documentation following the current official instructions; business financial records may be relevant to demonstrating the source of the gift funds specifically.
Use business records only for what they actually prove
If gift funds originate from the family business, document that source clearly and confirm it against current official instructions rather than assuming general business success is itself sufficient evidence.
A dated copy of the official page and FAQ as read, a written summary of the fee, gift and family terms on that date, the pending petition's receipt and priority date, and every question put to the official channel with the answer received. What counts as an acceptable alternative depends on the country and on the official instructions covering it — no universal rule imposes apostilles, certified translations or affidavits everywhere. Where a relative’s recollection differs from the paperwork, resolve it against the documents before anything is signed, and keep each person’s notices, identity records and correspondence in a set of their own so one account cannot be copied over another.