Overseas Travel and Receiving Texts

Online security being what it is these days, we use 2FA or Two Factor Authentication whenever possible while accessing accounts online.  If you're not doing this, you're at risk.

I elected to not pay Verizon $10/day to be able to use our Verizon ESIMs while in Europe (this feature is called Travel Pass).  Total cost would have been roughly $750 for our two phones, a bit high)

I went with a third party ESIM from Holafly (which sucks at activation processes, not recommended).  Cost <$3/day per phone; came to roughly $100/phone.

So, we had Internet access but Verizon ESIM had to be off.  Important caveat: the third party ESIM only provided internet access, no phone call capabilities.

This meant that when an online resource, such as our bank/credit card company wanted to verify it was me trying to login, it sent a text with authentication code to my Verizon mobile number as I'd previously set up.

Of course, my Verizon ESIM being turned off (and no Travel Pass), no texts so no authentication code.

Workarounds:

Best option:  Set up email as a 2FA authentication code option.  Not all companies offer this at this time however.

If email option not available, here's what worked for me and my Verizon account.  YMMV:

1.  While connected to good Wi-Fi Internet, go to your phone's SIM Manager and turn on the Verizon ESIM.  Leave your third party ESIM turned on.  

Note: enable a VPN if possible since you're accessing account credentials on a public Wi-Fi access point!

2.  Immediately, turn on Airplane Mode while ensuring Wi-Fi is still enabled!  (On my Android phone, SIM Manager is disabled when in Airplane mode)

3.  Queued up texts (sent to me while Verizon ESIM was off) would then start arriving, to include the 2FA text I needed in the moment.  Got the code, authenticated and was into my account.

4.  Once you're done, remember to disable airplane mode and immediately turn off the Verizon ESIM!

I also called Verizon support, while on Wi-Fi Internet and using my Google Voice number and had them remove Travel Pass from all mobile lines to prevent accidental activation of this feature and ensuing costs.

I believe the above workaround required Wi-Fi calling turned on.

You can receive texts but not send via Verizon ESIM.  You'll get a "trying to connect" error.

Texting while overseas was via apps such as Signal or Whatsapp.  It does require both parties to use the same app however.

You cannot make calls via Verizon ESIM when not using Travel Pass.  That's where Google Voice came in but it only works with US numbers!  If I ever travel overseas again, will have to do more research on this).

Almost bought another ESIM for voice calls in Spain but got by without; once Booking.com resolved internal issues which made bookings impossible when using our US credit cards.

Related Note/Caveat:

2FA via SMS texts is no longer as secure as it used to be.  Local authenticator apps are better but commercial entities aren't moving fast enough to implement this option