Image: Apple
Compare O2 iPhone Duo deals on Apple's first-ever foldable iPhone. This guide covers confirmed UK pricing from £1,999, what makes the Duo different from a regular iPhone, and whether it's worth the premium over the iPhone 18 Pro Max.
In short: The foldable iPhone that leaks spent months calling the "iPhone Ultra" has arrived as the iPhone Duo. Apple announced it alongside the iPhone 18 Pro and iPhone 18 Pro Max in September 2026. It opens up into a 7.6-inch inner display, 50 per cent larger than the iPhone 18 Pro Max's, and iOS 27 adds Split View multitasking and new ways to stand the phone up. It trades Face ID for Touch ID and has no telephoto camera. At £1,999 for 256GB, it's comfortably Apple's most expensive phone ever. Pre-orders open at 1pm on Friday 16 October 2026, with the phone on sale from Friday 23 October.
O2 iPhone Duo deals will appear on this page as soon as the network lists them. In the meantime, here's what Apple has confirmed, how the Duo stacks up against the iPhone 18 Pro Max, and what to weigh up before committing to Apple's first fold.
1. When is the iPhone Duo coming out?
Apple revealed the iPhone Duo at its September 2026 event, but it isn't arriving at the same time as the rest of the range. The iPhone 18 Pro and Pro Max go on sale on 18 September. The Duo follows over a month later, with pre-orders opening at 1pm on Friday 16 October 2026 and the phone on sale from Friday 23 October 2026.
Apple's genuinely new products often launch with limited supply, so expect availability to be tighter than a standard iPhone launch. Resale prices on secondary marketplaces are likely to run above retail for the first few weeks.
2. How much does the iPhone Duo cost on O2?
Apple has confirmed the following SIM-free prices in the UK:
| Storage | SIM-free price |
|---|---|
| 256GB | £1,999 |
| 512GB | £2,199 |
| 1TB | £2,599 |
| 2TB | £3,199 |
Pre-launch reports pointed to a US price of around $2,500 and a UK price comfortably north of £2,000. In the event, the entry model has come in just under that at £1,999, though the 2TB version tops £3,000. It's also £700 more than the 256GB iPhone 18 Pro Max.
On an O2 contract, a phone at this price makes the choice between 24 and 36-month terms particularly important, since spreading the cost over the longer term meaningfully reduces the monthly outlay. With initial stock likely to be limited, early O2 iPhone Duo deals may also carry stricter upgrade or trade-in conditions than usual, so check them carefully before you commit.
3. iPhone Duo specs: what Apple has confirmed
| Specification | iPhone Duo |
|---|---|
| Form factor | Book-style foldable |
| Inner display | 7.6-inch Super Retina XDR with nano-texture, ProMotion up to 120Hz |
| Outer display | 5.4-inch Super Retina XDR |
| Chip | A20 Pro with vapour-chamber cooling |
| Rear cameras | 48MP Fusion Main + 48MP Fusion Ultra Wide (no telephoto) |
| Front cameras | 12MP Center Stage + under-display FaceTime camera |
| Biometrics | Touch ID in the side button, not Face ID |
| Battery | Dual-battery system: up to 31 hours video playback (inner display), 44 hours (outer display) |
| Durability | Grade 5 titanium frame and hinge cover, Ceramic Shield, IP68 |
| SIM | eSIM only |
| Colours | Night Sky, Star White |
A genuinely new shape for iPhone
Image: Apple
Closed, the iPhone Duo is a compact phone with a 5.4-inch display offering more than 90 per cent of the screen area of the iPhone 18 Pro. Open it up and you get a 7.6-inch display, the largest on any iPhone, with a nano-texture finish to reduce glare. Apple says the inner display is flat and smooth where it folds. iOS 27 adds Split View so you can use two apps side by side, and new poses let you stand the phone up for hands-free FaceTime calls.
Touch ID makes a comeback
The pre-launch rumours were right: the iPhone Duo uses a fingerprint sensor, with Touch ID built into the side button, rather than Face ID. Regular glove-wearers may find this a slightly fiddlier way to unlock the phone than Face ID, though many people will barely notice the difference day to day.
A camera trade-off
Image: Apple
The Duo's 48MP Dual Fusion camera system has a Fusion Main and a Fusion Ultra Wide camera, with 2x optical-quality zoom and 4K 120 fps video. It has no dedicated telephoto lens, though, which both the iPhone 18 Pro and Pro Max include, so long-range zoom will be noticeably weaker than on the Pro Max. In return you get foldable-only features. Duo Preview shows the person you're photographing a live preview on the outer screen, and Kid Cue is designed to help get children looking at the camera.
Battery and cooling
Foldable phones have historically struggled with battery life, because a larger screen leaves less internal space for the cell. Apple's answer is an iPhone-first dual-battery system, with an eSIM-only design freeing up extra room for battery capacity. It quotes up to 31 hours of video playback using the inner display and up to 44 hours using the outer display, plus up to 50 per cent charge in around 20 minutes with fast wired charging. The A20 Pro chip is cooled by a vapour chamber for sustained performance.
4. iPhone Duo vs iPhone 18 Pro Max: which should you choose?
| iPhone 18 Pro Max | iPhone Duo | |
|---|---|---|
| Form factor | Traditional single-screen | Book-style foldable |
| Display | 6.9-inch | 7.6-inch inner, 5.4-inch outer |
| Cameras | Triple 48MP with telephoto | Dual 48MP, no telephoto |
| Biometrics | Face ID | Touch ID (fingerprint) |
| Starting price (SIM-free) | £1,299 | £1,999 |
| Best for | Photography, familiar experience | Multitasking, big-screen productivity |
If photography and a familiar way of unlocking your phone matter most, the iPhone 18 Pro Max is the safer, considerably cheaper choice. If you want the productivity of a genuinely bigger screen that folds away into your pocket, and don't mind paying a substantial early-adopter premium, the Duo is the one to go for.
5. Why buy the iPhone Duo on O2?
A phone this size and price benefits from a reliable network underneath it, and O2's UK-wide 5G coverage should make the most of the Duo's multitasking and streaming capabilities. Every new iPhone contract on O2 includes O2 Priority, adding early ticket access and dining perks on top of your plan. The Duo is eSIM-only, so make sure your O2 plan is set up for eSIM before the phone arrives.
6. What to expect from O2 iPhone Duo deals at launch
- Expect limited stock in the first weeks given this is a brand-new form factor for Apple, so pre-ordering promptly from 1pm on 16 October is likely to matter more than usual.
- Trade-in values on high-end current iPhones could help offset the Duo's £1,999 starting price if you're upgrading from a Pro or Pro Max.
- Resale demand on the secondary market is likely to run high initially, as it has with other first-generation foldables.
7. Should you wait, or buy an iPhone 18 Pro Max instead?
For most people, the iPhone 18 Pro Max will remain the more sensible choice. It has a proven form factor, a stronger camera system and a starting price £700 lower. The Duo makes most sense if you specifically want a foldable screen and are comfortable paying a significant premium for a first-generation device.
Compare the iPhone 18 Pro Max on O2 → for Apple's traditional flagship, or see the standard iPhone 18 if you're after better value.
8. iPhone Duo FAQs
Is the iPhone Duo the iPhone Ultra?
Yes. Before launch, Apple's first foldable was widely reported as the "iPhone Ultra", and earlier as the "iPhone Fold". It launched as the iPhone Duo.
When is the iPhone Duo coming out?
Pre-orders open at 1pm on Friday 16 October 2026, and it goes on sale on Friday 23 October 2026.
How much does the iPhone Duo cost?
From £1,999 for 256GB SIM-free, rising to £2,199 (512GB), £2,599 (1TB) and £3,199 (2TB).
Does the iPhone Duo have Face ID?
No. It uses Touch ID, built into the side button.
Is the camera as good as the iPhone 18 Pro Max?
Not for zoom. The Duo has two 48MP rear cameras and no telephoto lens, while the Pro Max has a triple-camera system including a 48MP telephoto.
Should I buy the iPhone Duo or the iPhone 18 Pro Max?
If photography and value matter most, the Pro Max is the safer choice. If you want a genuinely new foldable format and don't mind the premium, the Duo is worth it.
Specs and pricing are taken from Apple's UK website and will be updated as O2 confirms its iPhone Duo deals.
