Business documents
Speak to their accountant, ASIC registered agent, or business partner; check ABN and GST cancellation rules
Some steps differ by region inside the country.
Where
Their accountant, business partners, ASIC, and the ABN lookup.
How
Search ASIC and the ABN lookup by their name to find companies, business names, and registrations.
Ask the accountant for financial statements, tax returns, and ownership records.
Read any partnership or shareholders agreement, which usually sets out what happens to their interest on death.
Check for buy sell insurance that funds the purchase of their share by the surviving partners.
What to bring
A certified copy of the death certificate
The grant of probate
Company names or ABNs
Sources
This is practical information, not legal, medical, or financial advice.