Apple Watch Series 4's ECG Feature Will Work Internationally When Set to U.S. Region - MacRumorsOpen MenuShow RoundupsShow Forums menuVisit ForumsOpen Sidebar
Skip to Content

Apple Watch Series 4's ECG Feature Will Work Internationally When Set to U.S. Region

Apple revealed the Apple Watch Series 4 during an event in September, highlighting a new electrocardiogram (ECG) app that will be coming to users in the United States through a watchOS software update later in the year. Regulatory clearance is required for the ECG feature, and because of this it will be limited to the U.S. at launch, although the company is working on approval for other countries.

In a new post by 9to5Mac today, code found within iOS related to the ECG feature suggests that the ECG limitation is based on software, not hardware. This means that gaining access to the ECG app in a non-U.S. territory will be as simple as changing the region of the Apple Watch Series 4 and connected iPhone to the United States.

applewatchseries4ecgfeature
iPhone region can be changed by going to the Settings app > General > Language and Region, and then selecting the Region of your choice. Those who switch regions should note that the time, date, currency formats, and more will be affected by the change.

The ECG app on Apple Watch Series 4 works by placing a finger on the Digital Crown while wearing the watch. The electrodes in the Apple Watch detect the electrical impulses from your heartbeat and route the data to the S4, where it is converted into a signal for Apple's algorithms. This results in a heart rhythm classification that can vary between a normal rhythm to an atrial fibrillation. All of your ECG results are stored in the Health app in PDF format and can be easily shared with your doctor.

While the FDA has granted de novo clearance for the ECG feature, that's not the same as FDA approval and the agency does not recommend that the ECG feature be used by those under 22 or those who have already been diagnosed with atrial fibrillation. The FDA warns that Apple's ECG app is not designed to replace traditional methods of diagnosis or treatment and is intended for informational use only. The Series 4 is the first ECG product being offered over the counter directly to consumers.

Related Roundup: Apple Watch 12
Buyer's Guide: Apple Watch (Buy Now)
Related Forum: Apple Watch

Popular Stories

apple watch series 3 design

Apple Offers Steps to Fix Daylight Saving Time Bug on Apple Watch

Sunday November 1, 2026 3:34 am PST by
Apple has published a support document describing what to do if your Apple Watch continues to show time that's off by one hour after daylight savings time changes. "This incorrect time appears only on the Always On display when your wrist is down," says Apple. "When you activate the display by tapping it or raising your wrist, the time changes to the correct hour." To fix the issue, Apple says ...
siri recap live rewind

watchOS 27.3 Brings Live Rewind and Siri Recap to Apple Watch

Tuesday November 3, 2026 10:35 am PST by
With the first beta of watchOS 27.3, Apple is introducing new Audio Intelligence features it previewed for the Apple Watch Series 12 and Ultra 4 earlier this year. Powered by the S11 chip, Audio Intelligence includes Live Rewind, Siri Recap, Sound Recognition, and Shazam Music Recognition. Sound Recognition and Shazam are already on the watch, but Live Rewind and Siri Recap are now available ...
apple watch series 3 design

Apple Watch Users in Europe Report Daylight Saving Glitch

Monday October 26, 2026 5:26 am PDT by
Some Apple Watch users running watchOS 27 are reporting a daylight saving glitch after clocks went back in the UK and Europe on Sunday. In a MacRumors forums thread, five users – several in the UK and central Europe – say their watch shows the correct time when activated, but the Always-On display keeps showing summer time, leaving it an hour fast. The problem has also been reported in...

Top Rated Comments

tehStickMan Avatar
105 months ago
Sweet can't wait for it to tell me my heart PSI while Siri shows me that I'm 12 feet away from my next left-turn.
Score: 5 Votes (Like | Disagree)
105 months ago
FaceTime application is also software based and not hardware, yet it doesn't work for phones bought in countries where FaceTime is banned (even if US store or Location was selected).

The FaceTime App searches for the Model number from the approved list in Apple Servers or within the iOS itself and if it is not there it will simply not install nor show up in the APP store.

Therefore, i assume it will be the same thing for the ECG App, unless Apple makes an exception..
Score: 4 Votes (Like | Disagree)
105 months ago
Who in their right mind would ever think it was hardware based? Clearly Apple have not made two different watches - one type for US consumers and another for the rest of the world. :rolleyes:
Actually that's what I thought they did given that the cellular bands are different across different regions. The model numbers are certainly different between us/uk.
Score: 3 Votes (Like | Disagree)
105 months ago
Who in their right mind would ever think it was hardware based? Clearly Apple have not made two different watches - one type for US consumers and another for the rest of the world. :rolleyes:
Score: 3 Votes (Like | Disagree)
105 months ago
Should I be impressed with this? Either have it set to my country and have time/date/currency correct, or try to use the ECG (touted as one of the major features) and have basic functionality incorrect everywhere....
Actually changing the region seems to do much less than you would imagine; as far as I can recall it basically determines defaults for things like units, date display format etc - but crucially you csn still override these defaults to your preferred values.

When apple pay launched I tried setting my AW 0 region to usa and found I was able to use apple pay on it in London a couple of months before it launched in the uk. I was only able to link one of my wife's us credit cards since uk banks weren't supported, but other than that it worked great. As best I recall I was able to change pretty much all other settings to uk values so that the USA region didn't really bother me
Score: 2 Votes (Like | Disagree)
tromboneaholic Avatar
105 months ago
Has anyone actually tested switching region, doing an ECG and switching back to their original region? If that works, it would probably be a worthwhile update.
No one outside of Apple has been able to test it at all.
Score: 2 Votes (Like | Disagree)
Latest Stories
Siri AI Rumored to Become 'More Like an Agent' as Early as Next Year
Siri AI Rumored to Become 'More Like an Agent' as Early as Next Year
3 hours ago
Apple Taking New Approach to Developing iOS 28 and macOS 28
Apple Taking New Approach to Developing iOS 28 and macOS 28
5 hours ago
Early Apple Black Friday Deals on Apple Watch, MacBook Air, and More
Early Apple Black Friday Deals on Apple Watch, MacBook Air, and More
1 day ago
'Backglow' Lets You Customize New MacBook Pro's Glowing Apple Logo
'Backglow' Lets You Customize New MacBook Pro's Glowing Apple Logo
1 day ago
Top Stories: Apple Product Launches, iOS 27.3 Beta, and More
Top Stories: Apple Product Launches, iOS 27.3 Beta, and More
1 day ago
More Fun iPhone Duo Apps: 30 New Picks to Try
More Fun iPhone Duo Apps: 30 New Picks to Try
2 days ago
Hands-On With Apple's New OLED Touchscreen MacBook Pro
Hands-On With Apple's New OLED Touchscreen MacBook Pro
2 days ago
Apple Store With All-New Design Opening Soon in Southern California
Apple Store With All-New Design Opening Soon in Southern California
2 days ago
Control the Glowing Apple Logo on Your New MacBook Pro
Control the Glowing Apple Logo on Your New MacBook Pro
2 days ago
Apple Shares New 'Apple Card: Apply and Use in Minutes' Ad
Apple Shares New 'Apple Card: Apply and Use in Minutes' Ad
2 days ago
Apple Says More Than 100,000 Apps Optimized for iPhone Duo, Here's What's Still Missing
Apple Says More Than 100,000 Apps Optimized for iPhone Duo, Here's What's Still Missing
2 days ago
Early Black Friday Deals Kickoff With Steep Discounts on Apple Watch Ultras and More
Early Black Friday Deals Kickoff With Steep Discounts on Apple Watch Ultras and More
2 days ago
The MacRumors Show: iOS 27.3 Looks Like a Huge Update
The MacRumors Show: iOS 27.3 Looks Like a Huge Update
2 days ago
Best Buy's Black Friday Event Begins With Sitewide Savings on Apple, TVs, More
Best Buy's Black Friday Event Begins With Sitewide Savings on Apple, TVs, More
2 days ago
Apple Releasing Yet Another Two New Products Next Week
Apple Releasing Yet Another Two New Products Next Week
2 days ago
MacBook Air Drops to Lowest Price in Months With Amazon's $250 Discount
MacBook Air Drops to Lowest Price in Months With Amazon's $250 Discount
2 days ago
Apple Rumored to Drop the iPhone's Action Button Next Year
Apple Rumored to Drop the iPhone's Action Button Next Year
2 days ago
Apple's Extended Return Policy Now in Effect for 2026 Holiday Season
Apple's Extended Return Policy Now in Effect for 2026 Holiday Season
2 days ago
Apple Music Classical Updated With New Icon and Refreshed Design
Apple Music Classical Updated With New Icon and Refreshed Design
2 days ago
OLED iPad Mini, M6 iMac, and New MacBook Pros Available From Today
OLED iPad Mini, M6 iMac, and New MacBook Pros Available From Today
2 days ago
Apple Surveys iPhone Duo Buyers About Crease and Camera
Apple Surveys iPhone Duo Buyers About Crease and Camera
3 days ago
Apple's First Touchscreen Mac is Now Arriving to Customers
Apple's First Touchscreen Mac is Now Arriving to Customers
3 days ago
Claude Gets Personal Finance Feature With Bank Account Linking
Claude Gets Personal Finance Feature With Bank Account Linking
3 days ago
Apple Arcade Adds Crossy Road Rush and NBA 2K27
Apple Arcade Adds Crossy Road Rush and NBA 2K27
3 days ago
Apple's New HomeView Smart Home Hub: Here's How Much RAM It Has
Apple's New HomeView Smart Home Hub: Here's How Much RAM It Has
3 days ago
iPad Mini vs. iPad Air Buyer's Guide: Now Just $50 Apart
iPad Mini vs. iPad Air Buyer's Guide: Now Just $50 Apart
3 days ago
First iOS 27.3 and macOS Golden Gate 27.3 Public Betas Now Available
First iOS 27.3 and macOS Golden Gate 27.3 Public Betas Now Available
3 days ago
Apple Announces a New Mac Sales Record
Apple Announces a New Mac Sales Record
3 days ago
Paid $200 for Logic Pro? Apple Says You Won't Get This New Feature
Paid $200 for Logic Pro? Apple Says You Won't Get This New Feature
3 days ago
Instagram's Edits Video Editor is Now Available on Mac
Instagram's Edits Video Editor is Now Available on Mac
3 days ago