Lack of an ABN could mean suppliers would be forced to charge you penalty tax on any purchase. Dividends and interest received will not be liable for the tax. Conversely, bank interest and other related charges will not be available as Input Credits. The Government has now announced that amending legislation will be passed in due course regarding donations and collections made by such bodies. However, within the past few days the Government has advised that new legislation will be passed to remove claims from taxable amounts received.
Tax is payable if conducted by a registered body.
If registered, you are required to make quarterly returns. However you can elect to have monthly returns, particularly if you have regular expenses but a large part of your income occurs, say, once a year. These must be issued for any amount being charged out. These invoices must show the ABN of the provider and that GST is included. Obviously it is best not to pay a bill until the person has given you a tax invoice.