This is from the ATO site. Would appear companies pay quarterly too.
If you are an individual:
You have to pay PAYG instalments if the ATO notifies you of an instalment rate.
As a general rule, individuals who have shown gross business or investment income of $2,000 or more in their latest income tax return will be notified of an instalment rate, unless:
- the tax payable on their most recent notice of assessment is less than $500
- their notional tax is less than $250, or
- they are entitled to the senior Australian’s tax offset or pension tax offset.
If you are a company:
Generally, companies and superannuation funds will be notified of an instalment rate if:
- their ATO instalment rate is greater than 0%, or
- their notional tax is greater than $250.
However, if the gross business and investment income is greater than $2 million, companies and superannuation funds may only have the instalment rate option available to them.