So if it's not used sequentially, are you telling me that I can pick the days that I'll be using data? If so how?

You've activated the data, but just waiting to find a day to use it?

The FAQ states https://web.three.com.hk/esim/faq_en.pdf
"Customer can enjoy 10-Day roaming day pass in designated destinations within 90 days after eSIM activation.
...
10-Day pass can be consumed continuously or on a daily basis separately. Customer can enjoy the Roaming Data Day Pass in various destinations while travel on the same day.  Roaming Data Day Pass will be terminated on the respective end day of Hong Kong time 23:59 automatically and there is no pro-rata calculation even the Pass is effective in the middle of the day."

FAQ is also in small text at the bottom of this page: https://www.three.com.hk/eSIMMall/ch...x.jsp?lang=eng. Unlimited Data is higher speed data 500MB/day as noted by sixpaq and is stated in daily fair usage policy at the bottom of Terms & Conditions https://web.three.com.hk/esim/tnc.pdf. After that it gets throttled to min 128k.

Yes, I activated a 3HK esim and haven't used esim mobile data yet. I confirmed it latched to AT&T on roaming for several hours without enabling mobile data on esim. I didn't need it on my last trip and the 10-day pass will still be valid for the duration for my next trip. If I have the option, I prefer to activate and test top up reasonably ahead of time as top up/reload can take a while on different carriers (local acct only, topup resellers down, not available outside country, etc). Chalk it up to lessons learned with buying plenty of local and roaming sims and keeping some of them active.

Anyone have a recommendation for a carrier I can port my US T-Mobile number to so I don't lose it while abroad for an extended period?

Problem is, I'm already out of the country. Is Google Voice the only good choice here?

Voip.ms is the most widely recommended option, and the one I use as well.

It's probably my best option. I already use my primary Google account for another GV number but I suppose I can open another Google account and port my TMO number there?

Or is it possible to have two active GV numbers on one account? The docs are unclear.

Seems like I would transfer my TMO number to GV at which point my existing GV number would expire within 90 days, but I could pay $20 to make it permanent. Can anyone confirm from their own experience?

Before going too much further with this, since this doesn't really sound specific to eSIMs, perhaps start a new thread?

D'oh, thanks. I thought I was in the TMO global roaming thread.

T-mobile has finally has given Esim to postpaid plans. You have to call support or go into a store to get it activated. I was on the phone for 40 minutes and the person could not get it activated. I have to go to the store. YMMV

Why couldn't eSIM hardware copy the data from a physical SIM? Is there any reason this couldn't work? It would be a nice feature.

Well, went to a t-mobile store and spent three hours trying to get the Esim in place. The person was at the store was very helpful , but it was the tech support who didn't know what they were doing. Finally got it done.

I think it has to do with the fact that a SIM card is really a smart card, which performs encryption/decryption functions on-board. You can't really copy one smart card to another smart card. In case of physical SIM cards, your provider would have to issue you a new card and re-assign the phone number to it. In case of an eSIM, it will have to be reprogrammed. What I don't know is whether for each wireless profile, eSIM uses a different set of key pairs and different ICCID.

Thanks; I will try in my local T-mo store this weekend.

There's been a lot of great international roaming conversation here. I didn't see any discussion of the other use case for dual SIMs - having two phone numbers on the same device. My employer doesn't maintain any telephones at all. The expectation is we have a mobile number on our business cards, email signatures, etc. I'd like to get a second line added for work, so I can keep my 20+ year old personal number "clean". Any experiences with this?

Is using Google voice an option for you?