Airalo UK eSim and being able to receive text messages to U.S. phone number.

Yes, you can activate an eSIM and keep your original SIM in place to receive text messages. There should be a setting to select which SIM you want to use for each purpose (ie Calls/Messages/Mobile data in Android - find it under 'SIM Manager', and I imagine something similar for iPhone). The data roaming settings affects both SIMs - if you're using a local eSIM, then you can switch it off, but not sure with a travel SIM - it shouldn't have an impact because you've already set the phone to use the eSIM for data.

FYI, WhatsApp is not SIM sensitive - you do not need to change your mobile number if you have a new SIM in your phone, so you could just continue to use your US number of WhatsApp even if you don't have that SIM installed.

Thanks! I really appreciate the detailed response.

One point to check. When you start to use Airalo you turn on that eSIM and turn off your Us sim. I think you would be unable to send or receive texts. The easiest thing to do is have your family and friends set up WhatsApp using your US number. Once it’s set up they can text or call using WhatsApp regardless of which sim or eSIM you are using.

Does your US service have WiFi calling and texts?

One point to check. When you start to use Airalo you turn on that eSIM and turn off your Us sim. I think you would be unable to send or receive texts.

Not true. One does not "turn off" one's US SIM. One makes the European SIM primary for data, turning off data roaming for the US SIM. One then can continue to receive and send texts using the US SIM. I recommend also putting the US SIM on Do Not Disturb, making exceptions for family and important customers as appropriate.

Depending on how your US provider prices out texts when you're overseas, the idea of getting your friends and family to use WhatsApp to reach you might be a very good idea indeed. My provider gives me incoming and outgoing texts gratis, but other cell providers are less generous.

To Rocket: Yes we can do Wi-Fi text and calling but the particular text we needed to receive - was coming from an banking institution when we were away from Wi-Fi and they would not be using What’s App.
To Carol and Jphsbucks: Our younger family members are adept at What’s App but converting older family (85+ years but adept at basic smart phone features) is a bit more problematic.

That being said- thanks to everyone for helping me think through the whole process. No matter what eSim I use it is much better than the $ 10 dollar a day ATT international plan. We learned the hard way a few years ago -pre eSim that the $100 cap starts over when you cross a billing cycle thus costing us $200. Lesson learned.
Thanks again for all the help.

Here’s what worked for me last year when I went to the UK.

• US service is on Verizon through xfinity.
• UK service from EE. Purchased at shop in London

US service is set up as E SIM so I can’t lose the physical card. UK service was a physical SIM. UK service was set as primary and I turned off data roaming on my Verizon service. Text (SMS) messages came through but sometimes there seemed to be a lag. That can happen here at home too so might not be due to the set up. I had a friend call me on my US cell number. Came through to me on the street in London. He reported that it rang a few times before I picked up even though I answered at the earliest possible moment.

I was using an iPhone 11 Pro. In case you’re on iPhone here’s some more info from Apple on dual SIM usage.

https://support.apple.com/guide/iphone/use-dual-sim-iph9c5776d3c/ios

I’m just leaving a trip where I used an Airalo eSIM without a phone number. You can only get texts to your home number through WhatsApp or iMessage. If you set it up to get texts to your home number, they won’t work OR you’ll get charged for them. You either need to pay your provider for their international plan or give up phone calls and texts to the home number. Airalo does have phone numbers available, but that is what you were trying to avoid. Google voice can also be used for WiFi calling and texts but some companies, and I assume banks would be included here, won’t use google voice or similar services. See if the bank can confirm via an email. Using Airalo, Facebook and yahoo mail also wanted to confirm the user with the backup email, FYI.

Some comments:

1. When I had AT&T, I would buy an International add-on for $35 for 7 days, which included 5 gb. of data. I think $50 gave me 14 days and 15 gb. data. So it can be $5/day rather than $10.

2. Wifi calling works well, and most any newer phone will have that option, but that doesn't work with "normal" texting with your "normal" number, unless your carrier allows it. I think AT&T did, but not sure.

3. I switched to Tmobile, mainly because international roaming is either free, or much cheaper, depending on the country. Either way, texting is always free.

4. For 2FA from a bank, I agree they won't accept Google Voice, but for $8/month, I have a TextNow number with a locked-in phone number which does work with 2FA. I use it as a backup number for a variety of accounts. For $4 I bought a TextNow sim card, so I have free voice and texting from Tmobile towers. That's in the extra phone I bring on trips as a backup.

" you set it up to get texts to your home number, they won’t work OR you’ll get charged for them."

I'm surprised your telco charges you to receive SMS messages... the actual roaming should be free, including receiving SMS messages. You only pay to send SMSs or make or receive voice calls.

Basically what I do is keep roaming on, keep my home SIM in, so I can receive text messages, and answer the occasional important phone call. I only pay to answer calls. I use a second SIM (I have a dual SIM phone) or eSIM for data.

In terms of bank 2FA/one time passwords, all my banks except one use app authentication rather than text messaging as it is more secure - both for accessing internet banking and authorising credit card transactions online. This may be an option.