A US firm is to extend its free mobile data, voice and text offering to the UK from July this year.
FreedomPop will offer Sim cards that offer 200MB of data, 200 texts and 200 minutes of voice calls per month using the cellular network at no cost.
The company already offers a similar free mobile data plan in the US to more than half a million users.
The firm, which is backed by Skype founder Niklas Zennstom, says it will make money by selling extra services.
The company told the BBC it plans to make money from selling users additional data beyond the amount offered free of charge and additional services for which it will also charge.
These include the ability to roll over unused data to the next month, anonymous browsing to protect online privacy, and the ability to add a second phone number from more than 60 countries so that friends and family outside the UK can call at local rates.
For example a UK subscriber could operate a US-based number from the Sim card in addition to their normal UK number for a £2 per month charge.
"We see ourselves as the no-frills mobile carrier. We want users to feel liberated, getting the basic services for free," FreedomPop co-founder Steven Sesar told the BBC.
"We'll start with around a dozen add-on services that customers can choose to pay for and extend that to 20 or so within a year."
Wipe out competitors
The company already has around one million subscribers in the US, with 51% on just its free package, with 49% paying for additional data and services.
The US free deal is more generous than the one proposed for the UK, offering 500MB data, 500 voice minutes, and 500 texts at no cost.
Explaining the difference Mr Sesar said: "We found users in the US typically use more data and the alternative plans start at around 500MB."
"In the UK there is a lot of interest in the lower-use end of the market which is where we plan to wipe out the guys offering £5-£10 data plans."
Too good to be true?
Commenting on the plans mobile expert at uSwitch.com Rob Kerr told the BBC:
"A free Sim with a free allowance of minutes, texts and data might sound too good to be true, but it could just be enough to appease the truly entry-level customers.
"The more data-hungry users should be careful about out-of-bundle charges and make sure they do their research before they go over their allowance.
"Extra data charges will have to be very competitive with the likes of iD Mobile offering unlimited data at £20 a month.
"Where FreedomPop could be useful is for that emergency phone in the car, where users are unlikely to eat into the limited calls, texts and data."
FreedomPop said it will offer its Sim cards over the internet and wants to hear from people in the UK who would be interested in helping test the service before its official launch.