Ask HN: What's Your Experience with eSIMs?

41 points by zikohh ↗ HN
As a tech enthusiast, I'm always excited to dive into the latest advancements, but sometimes, new technology comes with its own set of challenges. Unfortunately, these challenges can turn a fun experience into a frustrating ordeal, especially when the surrounding systems aren’t quite as reliable as they should be.

Recently, I decided to upgrade my SIM plan on O2, the UK's largest mobile network operator. At the time, I was using a physical SIM card but was intrigued by the idea of switching to an eSIM. eSIMs offer some great benefits, like the ability to use two numbers on a single-slot phone and the added security of not being physically removable, though the latter wasn’t my main concern.

I was using an Android device when I made the switch, and a few months later, I upgraded to a new Android phone. The O2 app allowed me to install the eSIM on my new device, but I quickly ran into trouble. Despite following the installation steps, my phone had no signal. The dreaded notification 'SIM 2 not provisioned' kept popping up. I tried everything—deleting and reinstalling the eSIM multiple times, leaving it overnight in hopes it would activate, and even turning off the old device to avoid conflicts. Nothing worked.

In a last-ditch effort, I deleted the eSIM from my old phone entirely, thinking that might solve the problem. But that only made things worse—now I couldn’t install the eSIM on any device. When I called O2 for help, they informed me that their system still registered my SIM as a physical one. To make matters worse, the system was stuck in a processing state, waiting for the eSIM installation to complete before moving forward. Their advice? Wait for 3-5 days for the process to time out because there was nothing else they could do—not even a visit to the store would help.

So here I am, stuck in a tech limbo, waiting for time to do what technology couldn’t. It’s a stark reminder that while new tech can be exciting, it’s not always smooth sailing.

What's your experience?

75 comments

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I needed dual sim so I could separate work from private. Ordered a Canadian Samsung s20 because their dirt cheap that had 2g support. Reflashed it with American firmware and now I have no 2g/3g support but do have dual sim (turns out same hardware in the devices they just use rom to change featutes based on where in the world you are as the base chip it worked on supported all of them).

I use the esim for work. Works great transferred a real sim to it via online portal, cost me $120aud for whole year plan, unlimited calls and text.

What a ride

Personally, I used them with great success traveling RTW. Being able to still use my home number (on rare occasions) while having a cheap local eSIM was great. Usually just for data (navigating) but sometimes having a local number was also useful. The apps generally sell overpriced eSIMs, unsurprisingly, but are very convenient. Don’t really have a reason for two sims in my home country though.

iPhone 15 fwiw

I’ve had my iPhone on eSIM (T-Mobile and Verizon) for the last 3-4 years with no issues.

Sorry to hear you’re having issues.

I used eSIM for traveling - it's been such a joy to have a full working data plan in another country the moment I touch down in the country.

https://redgreenrepeat.com/2024/05/12/traveling-and-your-int...

From your post and experience - I can see eSIM would be a rough experience - my main line at home is still a SIM and the eSIM is optional

eSIM is amazing for purchasing roaming internet while traveling. There is a eSIM aggregator that I can recommend: https://esimdb.com/
Urgh some of those are crazy expensive. Best to pick by destination if you can.

For example they charge you $23 for 10 gig in Central Asia there but if you get a local eSIM it’s $5 for the same and $10 for unlimited. I just WiFi hopped because there was bugger all reception out there anyway.

they also work as soon as you get off the plane! so you don't have to waste time buying an overpriced SIM at the airport while jet-lagged in a foreign language at a kiosk that may be closed.
I am using https://www.dent-app.com/ for travelling and never going back.

I would also use eSIM for the main SIM, but the local monopolist telecom do not give this option yet.

Dent looks really cool thanks for sharing!
I use a Helium Mobile eSIM, which I pay with crypto. I set it up in something like 10 minutes when I became eligible for an account. No problems so far.

I've also had eSIMs from FirstNet and AT&T, no problems there either. Running dual-sim hasn't been a problem either on any of my Galaxy or iPhones.

I won't run my primary as an eSIM as it's just way too much aggro to move it between phones if needed, and you're well and truly stuck if you need to reprovision but don't have a Wifi connection.

We've just switched mobile providers at work, and the eSIMs were a monumental headache. A lot of it was user error, but ultimately it's hard to cock-up taking a physical SIM out and putting a new one in.

As a secondary they're great. I had awful speeds on Lebara in Prague on my main SIM, so grabbed a 3-day one off Nomad just for data.

super great as secondary sim (I mean internet)

I experienced some, but to me https://etravelsim.com/ is good choice (europe and balcans)

support impressive (super responsive) plus you get a uk number, free calls to other their esim... just discovered this e-sim world thanks to HN: it is the future

etravelsim is where I got a 4gb esim for traveling in a few Mediterranean countries recently. Worked great and was cheap. Only issue I had was apps that were dependent on a phone # like WhatsApp acted a bit weird. But other than that everything else worked just fine.
I've tried travel eSIMs (Ubigi) on a couple of trips to Japan. In my experience compared to when I've gone and used physical SIMs, the reception and coverage wasn't nearly as good. Just super random neighborhoods and areas where the phone just completely drops connections. Even the top of a mountain near Fuji, my eSIM failed completely but my Japanese friends with eSIMs had completely normal and fast service despite supposedly being connected to the same network (DoCoMo iirc at the time).

Not sure if it's an eSIM issue or that the service (Ubigi in this case) that fronts the cellular network just can't operate it smoothly or what.

I can say for certain of course, but I would guess at that being the result of the poor service that travel network providers typically offer. I have also used travel eSIMs in Japan and had generally a pretty poor experience (bad coverage and slow speeds). Conversely, I've had non-travel, regular monthly eSIM contracts in both the UK and Germany and experienced few issues (at least no more than my experience with physical SIM cards).
> Not sure if it's an eSIM issue or that the service (Ubigi in this case) that fronts the cellular network just can't operate it smoothly or what.

Or the bands supported by your phone. Could be any of these possibilities

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Works great on iOS but can be a bit fidgety. I bought a data-only eSIM for Switzerland and as I crossed the French/Swiss border I had to go deep into the settings menu to enable the eSIM, set it as the data primary and keep using my primary SIM for phone calls and FaceTime, but then also disable data roaming on my primary SIM as to not accidentally occur charges in case reception of the eSIM fails. And disable roaming on the eSIM so I wouldn't occur extra cost if it connected to the French network, as I was close to the border. When going back to France I would disable the eSIM, set the data primary back on my primary SIM and enable data roaming on that SIM (after waiting for it to connect to the French network).

It would be nice if there was a more hands-off approach when crossing a border, or some sort of "do whatever is going to cost me the least amount of money" approach to roaming and having two SIMs.

I've never used one but am biased against them because they seem like a step toward a future where it's impossible to unplug a device from The System at all.
It's been great for me. I just went to Europe and used an eSIM with a different plan while I was there. The biggest issue is that it required some unique settings deep in the iPhone config, but once those were properly set it all worked great.

Also it was kinda cool having two lines for a day before I left.

Airalo works well on my iPhone for travel. I had super fast data in Europe (including UK), Japan, Mexico.

IIRC the rates are not competitive compared to local plans though, so not sure if it's worth it for you.

This is the fateful combination of O2 and Android together, possibly the worst experience in the universe (from experience). Nothing but trouble for years.

I dumped my Pixel 6A and O2 a couple of years back after a roaming shit show in Iceland where they billed me £400 and went iOS and Giffgaff. Despite giffgaff being the same company in theory keeping a physical sim with them has been trouble free. And I just add an additional eSIM when travelling wherever and everything just works! Giffgaff gives you 5Gb of roaming a month as well in Europe which is good enough for the odd weekend here and there if you are careful and enable low data mode.

I got a prepaid eSIM from O2 this summer and then traveled through Europe. It worked great, got some 50GB of traffic for a month, had no connectivity issues.
Found it to be a really unpleasant experience using Airalo in Europe on an iPhone. Maybe user error, but everyone in our group had confusing issues. Lots of problems with the phone forgetting the home number meant it was hard to get messages with iMessage, and no SMS caused a big mess with local businesses and with 2 factor/fraud detection. No phone number was also an issue a few times. I don’t know what we did wrong, but it was really frustrating.
This is on you for relying on SMS. Switch to a proper 2FA app or at least to Google Voice.
I find SMS in roaming quite an adventurous endeavour anyway. Some will come, some will get quietly lost, some will err in sending, some will come in many copies at the same time of day (I'm looking at you MMS), some will arrive only when I'm back home, it's a total mess.
I have two lines on my iPhone. One is an eSIM (AT&T), and the other is a simSIM (T-Mobile).

I don't travel internationally, these days, so I know that I'm not a "power user," but my experience has been great.

Does what it says on the tin.

From what I hear, Apple is considering going all eSIM, on future phones. There may be nations, where that won't wash, though.

> Apple is considering going all eSIM, on future phones

Already there. My iPhone 15PM does not have a SIM slot, and I think that is true for the entire iPhone 15 lineup.

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Totally smooth experience on my Pixel 8, both in home country (for dual sim) and when travelling.
same on a pixel 7. Super smooth experience with a mexican and multiple US mvnos.
Using Airalo plus a Verizon physical sim in Europe with an iPhone SE 2 worked, and I found the cost fair enough, but it drained my battery like mad, so bad in fact that I found myself turning the eSIM off a lot. I think this is probably just Yet More Shoddy Apple Software, and I will probably use eSIM in future, but it’s something to watch out for.
I can't imagine how SIM vs eSIM would make any difference, I would ascribe battery drain to something else tangentially related, like using a mobile network with weak coverage that has the phone constantly ramping up power to find a decent signal.

Anecdotally, I've used three eSIMs in my iPhone 15 (only two are allowed to be active at the same time, though), and my wife has a physical SIM and an eSIM on her older iPhone, and we've not experienced any weird behavior.

I did a fair bit of googling on this as it was my first time using eSIM. Apparently for iPhone the network switching eats the battery, whereas for Android (which has had dual-sim support for ages) it’s not a problem.

Nothing else changed in my usage, and eSIM only worked fine, it was just when the physical sim and the eSIM were both active that the battery drained super fast (like more than double the usual rate).

YMMhaveV of course.

I love the convenience of physical SIMs. Will hate the day when I don't have a choice but to 'upgrade' to eSIMs.

I have a phone with dual physical SIM card slots. I can go to any country in the world, buy a SIM, put it in, and am up and running. eSIM provisioning at airports is barely available in few coubtries.

I broke the display of my phone? Easy, remove the SIM and put it in a spare phone and I can still make and receive calls.

You can buy eSIMs before you reach your destination fyi. Used them in Europe and India through Airalo after buying them in the US.
Not sure why you attracted downvotes with that comment. It's 100% correct. You can buy an eSIM while still in the US and just leave it turned off, then flip it on when you get to your destination. Some providers do still advise waiting to install the eSIM until after you reach their home territory, but that's not any more difficult.

We just did exactly this a couple weeks ago when we went to the UK & France. Super easy, as soon as the plane took off I toggled roaming off on my regular US line, and turned on the traveling eSIM when we landed. Bam, phone works as normal, still gets calls and texts, etc, but way cheaper than paying roaming charges.

SIMs are one of those things that work so well they shouldn't be touched - which doesn't mean doing away with progress (ie. eSIMs) - it means both should coexist.-
I was banned by Total by Verizon for moving my SIM into a different phone. Does it just work with other carriers?

Happy ending though, I switched to US Mobile with an eSIM and disputed the monthly charge by Total on my credit card since I paid for service not provided.

It pretty much works with other carriers. My spouse has Verizon prepaid, and when they get a new phone, just pop the sim out of the old phone and put it in the new one. Same thing with t-mobile US prepaid for me. Around the world it's even more common to just move sims around.

Especially around the turn down of 3g, some US carriers were picky about the phone you used (must support VoLTE on their network or not allowed on a phone plan), but to my knowledge they wouldn't ban your sim, maybe just the phone after some notifications.

Had it for years. The security, convenience and not having to wait 2-3 days for a replacement is great. At work they haven’t supplied users who select an iPhone with physical SIM the last two or so years. Even my mom had her new phone set up with an eSIM. Never heard of any issues, and our department has 100s’s of devices with eSIM.
eSIMs are fantastic! Except that they just make me even more irate with various service providers that don't work with them, or don't work with the VOIP number that I use when using data-only SIMs.

Seriously, my Airbnb account has been broken for TWO MONTHS because Airbnb:

1. Uses SMS (only) for 2FA. For a fucking international travel company.

2. They don't support VOIP numbers for SMS 2FA. An issue I reported to them at least 4 times over the past 2 years.

I'm sorry, but what the fuck is wrong with people. Not everyone uses an iPhone, and even then, I'm pretty sure those iPhone carriers will NOT DELIVER SMS WHEN IM IN THE MIDDLE OF NOWHERE.

If I could donate 10% of my salary to just sending boxes of dog shit to the AirBnb C-Suite, I would.

In between this and hidden cameras, I am better off not using Airbnb.
One nice thing about eSIM is if someone steals my iPhone, they can’t remove the SIM card and keep the device offline.