UNLIMITED data is the new battleground for telcos after two of the nation’s biggest providers announced an all-you-can-eat deal.

The nation’s biggest telco, Telstra, today revealed its first smartphone plan providing customers with unlimited data.

It comes ahead of a scheduled announcement by rival telco Vodafone who were due to reveal later today they were rolling out unlimited data plans.

The deals will allow phone users to chew through as much data as they wish without the worry of overindulging and being slugged with higher monthly bills.

The announcement also comes just two months after rival telco Optus rolled out unlimited data deals for a short period but then quickly pulled the offers from market.

It was a public-relations nightmare for the telco who remained tight-lipped as to why the super-sized plans were removed within hours of going live in March.

But Vodafone will be getting in first - their unlimited data deals begin from Wednesday and will give customers three price points - $60, $80 and $100 deals - where they can sign up to unlimited deals.

The catch is the data speeds slow as certain points - on a $60 plan at the 30GB mark, on a $80 plan at the 60GB mark and on a $100 plan at the 100GB mark.

Vodafone’s consumer business unit director Ben McIntosh said the deals have put heat on the telco market.

“We don’t restrict what you can do with your data, unlimited means unlimited,’’ he said.

“If you are on these plans in Australia there is no way to rack up bill shock with data anymore.”

From Thursday Telstra will give customers on a $69 per month 12-month plan the Endless Data BYO deal which includes unlimited data.

But there’s a catch — up to 40GB of data is at uncapped speeds before it drops to a slower pace

The following data consumption for the month will slow to 1.5Mbps which Telstra say will still allow customers to stream video in standard definition, listen to music, browse the web and access social media.

Telco comparison website WhistleOut’s spokesman Joseph Hanlon said “unlimited data has been one of the most requested phone plan features for years.”

“Truly unlimited mobile phone plans could change the way that many of us accessed the internet entirely,’’ he said.

“Rather than having separate phone and internet plans, we’d simply connect all our devices to our phones and use a single account for everything.”

“Throttled data speeds mean that even if you do manage to hit your full speed data limit you will never pay extra at the end of the month.”