Customers who order the device by April 19 will be able to get the handset eight days before its official launch.
The phone comes in two sizes and two different colours - the S8 and S8 - and will officially be available to buy in theUK on April 28, with the S8 costing 689 and the S8 779.
It comes with a larger screen that fills up most of the face of the device and the home button has been removed in favour of a pressure sensitive "invisible" home button embedded in the display screen.
The S8 has a 5.8in screen and the S8 a 6.2in display, with both devices also becoming the first to house the tech giant's new artificial intelligence software, virtual assistant Bixby It's the first phone from Samsung since the Note7 was discontinued over safety concerns and battery fires Both devices come with a 12 megapixel rear camera and an eight megapixel front-facing camera, as well 64GB of storage that can be expanded up to 256GB via a MicroSD card slot.
The S8 and S8 are also both dust and water resistant and have fast charging capabilities.
If you're already in a contract then the best way to find a new deal is by using a comparison service to match you to your perfect plan.
Billmonitor compares your previous three months usage to work out how much you're actually using. You'll need to sign in using your details from your online mobile account.
It only works for customers of EE, O2, Tesco Mobile, Three and Vodafone.
Another similar comparison tool, MobilePhoneChecker has a similar feature to Billmonitor but it's not as comprehensive.
Mobile firms are clever. They know people want to get the latest smartphone as soon as possible at a price that seems manageable but when you add this up, you might realise you're overpaying.
For example, a network offering you a 45 a month contract over 24 months with an upfront cost of 99 = 1,179 Once you minus the cost of the handset (1,179 - 689) you will see that you're really paying 20.41 a month for your contract.
One of the most cost-effective ways to buy the iPhone is by buying it up-front - but with a hefty 689 price tag this might not be possible.
If you can then it's worth looking at SIM-only deals as they generally offer a cheaper alternative than getting a contract with the network.
The best contract deal depends on how much you use your phone. We take a look at what each network or phone shop is offering an pick out some of the best deals:
We pay for your stories! Do you have a story for The Sun Online Money team? Email us at or call 0207 78 24516