In most cases, if your client changes their business structure they will need to cancel their existing Australian business number (ABN) and apply for a new one as they may no longer be operating under the business structure for which they received the ABN.
Before changing a business structure your client should understand the impact this will have on their business and clients. This may include changes to tax obligations and other business registrations.
Examples of when they need to cancel their ABN:
Read more about business structures as they relate to ABN registration.