Being proactive by prepaying your tax in advance is a great idea. 

This will help you budget for next year's income tax, smooth out your cash flow, and you reduce the likelihood that you will have to pay a large tax bill when you lodge your tax return. There are a number of ways to do this using ATO online services.

If you’re an individual taxpayer or sole trader, you can request to voluntarily enter the PAYG instalment system online through myGov.

You can also request voluntary entry into the PAYG instalment system through your registered tax agent or by phone on 13 28 66 for businesses.

Alternatively, you can make prepayments at any time and as often as you like through ATO online services, sole traders can use myGov to do this and businesses can do this by using Online services for business.

The ATO will hold prepayments you make towards your expected bill unless you, or your agent, request a refund of that money