O2 opens pre-orders for HTC One M9 and Galaxy S6 and S6 Edge

O2 Refresh customers who pre-order the latest HTC and Samsung smartphones will also get a free Fitbit Charge

O2 has today opened pre-orders for the HTC One M9 and Samsung's Galaxy S6 and Galaxy S6 Edge on its O2 Refresh tariff. Customers can pre-order their phone of choice either online or over the phone, and everyone who does so will receive a free Fitbit Charge for their trouble, too.

All three phones are available on a range of price plans, but the HTC One M9 comes in as the most wallet-friendly. For instance, 2GB of data and unlimited texts and minutes will only set you back £38-per-month with an upfront cost of £49.99 if you choose the One M9, whereas the same deal on the Samsung Galaxy S6 Edge costs £48-per-month with an upfront cost of £99.99.

These tariffs won't last for long, though, as O2 will be updating these tariffs on its website next Thursday 26 March. Alternatively, anyone pre-ordering the phone in-store will have to put down a £49.99 deposit. They will then be able to choose one of the new tariffs when they collect their phone.

This will be good news for anyone who bought an HTC One M8 or Samsung Galaxy S5 last year, as O2 Refresh allows users to switch devices whenever they like without charge. Likewise, O2 will be offering up to £171 for customers' old One M8 and up to £175 for their old Galaxy S5s through O2 Recycle when they upgrade. O2 Recycle is available in-store and online.

As an added sweetener, anyone who pre-orders the One M9, Galaxy S6 or Galaxy S6 Edge will receive a free Fitbit Charge fitness tracker. As well as recording your daily activity and giving you real-time fitness stats, the Fitbit Charge has built-in Caller ID, allowing you to see who's calling from your wrist when you're out on a run, for example, and your phone's in your back pocket.

We'll be bringing you our full in-depth reviews of the One M9 and Galaxy S6 phones in the coming weeks, so be sure to check back soon to see which will reign supreme over the coming year and which is the best one for your budget.