Apple Watch Series 12 needs an iPhone 11 or later running iOS 27, according to Apple’s tech specs, and the pairing itself takes about eleven steps. The reward on the first morning is a Readiness score, a number from 0 to 10 that Apple’s press release says is built from recent activity, training load, vitals and sleep.
This guide covers the setup as Apple documents it, what the watch needs to collect overnight before it can score you, and how to read the four recommendations. The pairing steps come from Apple’s current Apple Watch setup page, written for watchOS 26 and iOS 26. Series 12 needs watchOS 27 and iOS 27, so a prompt or two may look different, and Apple has not yet published a support article for the Readiness score.
What you need before pairing
- An iPhone 11 or later, including iPhone SE (2nd generation or later), with iOS 27 installed. iOS 27 ships Monday, September 14, four days before the watch.
- Bluetooth on, and the iPhone connected to Wi-Fi or cellular.
- Your Apple Account password, and a passcode in mind for the watch. Apple says a passcode is required for Apple Pay.
- A recent backup if you are replacing an older Apple Watch and want to restore it.
How to set up Apple Watch Series 12
- Press and hold the side button until the Apple logo appears.
- Put the watch on your wrist.
- Hold your unlocked iPhone near the watch and wait for the setup prompt.
- Choose Set Up for Myself, or Set Up for a Family Member if the watch is for someone without their own iPhone.
- Center the watch in the viewfinder of the Apple Watch app on your iPhone.
- If the camera cannot read it, tap Pair Apple Watch Manually and follow the prompts.
- Choose to set up as a new Apple Watch or restore from a backup.
- Sign in with your Apple Account.
- Create a passcode.
- Choose your settings, including text size and health options.
- Keep the iPhone and watch close together while they sync.
The health options step matters for Series 12 in particular. The Health Sensing System Apple describes on its Series 12 launch reads heart rate every five seconds and HRV every five minutes, and the Readiness score depends on those readings plus a night of sleep tracking.
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What feeds the Readiness score
Apple’s press release describes Readiness as one simple score each morning, on a scale of 0 to 10, that updates through the day as new data comes in. It draws on four inputs, all of which the watch collects on its own once it is worn.
| Input | Where it comes from | What it needs from you |
|---|---|---|
| Recent activity | Activity rings and workouts | Wear the watch during the day |
| Training load | Workout intensity over 7 days vs 28 days | Log workouts; edit the effort rating if it looks wrong |
| Vitals | Overnight heart rate, HRV, respiratory rate, wrist temperature | Wear the watch to sleep |
| Sleep score | Duration, bedtime consistency, interruptions | Set up Sleep tracking and wear the watch overnight |
Apple’s Vitals guide notes it takes time to establish a typical range for each metric, so the first score may sit on thin data. Wearing the watch for the first few nights gives Readiness and Vitals the baseline they compare against.
How to read your first score
- Wear the watch overnight after setup. Sleep tracking is the one input you cannot skip.
- In the morning, open the Readiness app on the watch, or the Insights tab in the redesigned Health app on iPhone, which Apple says includes readiness alongside heart, sleep and vitals summaries.
- Read the number from 0 to 10 and the recommendation beneath it.
- Check back later in the day. Apple says the score updates as new data comes in, so a hard midday workout can change the evening reading.
The four recommendations Apple lists are Recover, Pace Yourself, Ready and Go For It. Apple has not published the thresholds that map a score to each label, or how the four inputs are weighted.
If pairing fails or the score does not appear
- No setup prompt on the iPhone: confirm iOS 27 is installed. Apple’s specs make it a requirement for Series 12, so an iPhone still on iOS 26 will not see the watch.
- The camera will not read the watch face: tap Pair Apple Watch Manually.
- No Readiness score in the morning: the watch was not worn overnight, or sleep tracking is off. Apple’s Sleep score guide says the score appears in the Sleep app after you wake.
- The score seems stuck: Apple says it updates throughout the day. Give it a workout or a night of sleep before judging it.
- Vitals notifications are quiet: they only fire when at least two metrics fall outside your typical range, and that range needs several nights to form.
Series 12 starts at $399 for the 42mm aluminum model, pre-orders are open now, and the watch reaches stores on Friday, September 18. Apple’s event recap covers the rest of the lineup, including Ultra 4 and the ceramic Series 12.
