Which is the competent authority for Australian invention patent applications

Whether an Australian industrial design application can be type-converted

no

Australian invention patent application authorization and annual fee instructions

Grant fee: should be paid within 3 months after receiving the granted notice
Annuity: From the 5th year from the filing date, the annual fee should be paid before the filing date of each year. If the annual fee is overdue, the payment can be postponed to a grace period of 6 months, but a penalty of AUD 100.00 is required every month

How long is the protection period for utility model applications in Australia?

For innovation patents that have ceased application on August 25, 2021, the innovation patents that have been applied for can still enjoy the corresponding 8-year protection period.