Hobby or Business?
A hobby is a spare time activity or pastime pursued for pleasure or recreation. Unlike a hobby, a business is run with the intention of making a profit and has basic reporting requirements such as declaring income and claiming expenses.
If you determine your activities are a hobby, you don't have any additional tax or reporting obligations. You should check regularly to make sure your activities still qualify as a hobby.
If your activities are a hobby but you supply goods or services to businesses, they may request your ABN when they pay you. As you don't need an ABN, you can use the Statement by a supplier form to avoid the business withholding an amount from their payment to you for not having an ABN.
See the ATO information on this topic here
If you would like to discuss this or any topic further please email: firstname.lastname@example.org