It is a separate tax but a way to paying your income tax as you receive income through the year. If you residual income tax is more than $2,500, you’ll have to pay provisional tax for the following year.

There are 3 options that you can choose from-standard, estimation and ration.

Due dates for provisional tax

/* Max width before this PARTICULAR table gets nasty. This query will take effect for any screen smaller than 760px and also iPads specifically. */ @media only screen and (max-width: 760px), (min-device-width: 768px) and (max-device-width: 1024px) { /* Force table to not be like tables anymore */ table, thead, tbody, th, td, tr { display: block; } /* Hide table headers (but not display: none;, for accessibility) */ thead tr { position: absolute; top: -9999px; left: -9999px; } tr { margin: 0 0 1rem 0; } tr:nth-child(odd) { background: #ccc; } td { /* Behave like a "row" */ border: none; border-bottom: 1px solid #eee; position: relative; padding-left: 50%; } td:before { /* Now like a table header */ position: absolute; /* Top/left values mimic padding */ top: 0; left: 6px; width: 45%; padding-right: 10px; white-space: nowrap; } /* Label the data You could also use a data-* attribute and content for this. That way "bloats" the HTML, this way means you need to keep HTML and CSS in sync. Lea Verou has a clever way to handle with text-shadow. */ td:nth-of-type(1):before { content: "Category"; } td:nth-of-type(2):before { content: "1st Instalment"; } td:nth-of-type(3):before { content: "2nd Instalment"; } td:nth-of-type(4):before { content: "3rd Instalment"; } td:nth-of-type(5):before { content: "4th Instalment"; } td:nth-of-type(6):before { content: "5th Instalment"; } td:nth-of-type(7):before { content: "6th Instalment"; } }

Category	1st Instalment	2nd Instalment	3rd Instalment	4th Instalment	5th Instalment	6th Instalment
Not registered for GST	28 August	15 January	7 May
GST-Registered-6 monthly filer of GST returns	28 October	7 May
GST-Registered-one-or two monthly filers of GST Return	28 August	15 January	7 May
GST-Registered and elected to use the ration option for provisional tax	28 June	28 August	28 October	15 January	28 February	7 May