Media and retail industry leaders have backed Treasurer Joe Hockey's plan to hit multinational companies with what's been described as a "Netflix tax" on digital downloads.

Mr Hockey unveiled on Monday new measures to crack down on tax avoidance by multinational companies and extend the GST to digital purchases, such as Netflix's video streaming service.

Who are the winners and who are the losers from Treasurer Joe Hockey's budget? Credit:Andrew Meares

The Treasurer said the changes were designed to create a "level playing field" and expected to reap an extra $350 million in revenue for the states.

Netflix, which has a market cap of $US34 billion ($43 billion) undercut its local competitors Stan and Presto by $1 a month, or 10 per cent – the same rate as the GST – when it launched its Australian service in March.