Desexing is recommended not only to prevent unwanted litters of kittens (which may contribute to feral cat populations), but also for many health benefits.
Benefits of desexing include:
Your kitten should be desexed by 4-months of age. If your kitten is not desexed by this time, you will be required to pay an annual permit under NSW Government law. Your veterinarian can update the pet registry if they believe your cat should not be desexed for medical reasons.
The cost of desexing will vary between males and females, as well as potential complicating factors (such as undescended testes in males, and females that are currently in heat or are pregnant).
Your kitten should have a consultation with a veterinarian prior to their desexing procedure to ensure they are in good health.