(Killing time on a train. This is a bit lengthy)

1. Google Fi’s premium plan is THE BEST for international roaming. You have 50gb/mth of high-speed data, not the much slower 256k that T-Mobile or others would offer you. 50gb is a ton and includes up to 5G speeds.
2. You must activate your Fi sim while still in the US. Don’t plan on bringing an unactivated sim just in case.
3. You WILL be cut off of data roaming exactly after 3 months abroad but calls are still available (.20/min) and texting is still free to/from US numbers.
4. They’ll mail you a free sim card, takes about 4 days. If it doesn’t arrive in time then no worry as Best Buy carries Fi sim cards usually and you’ll probably only have the option to buy with 60$ credit but it’s all the same as you have no commitment when ordering the free card if it doesn’t make it.
5. Calling over wi-fi with Google Fi has not been consistent but a different brand phone may react better. I mostly use Google Voice to make/get calls for free to US numbers as well as calling 1-800 numbers. Some companies won’t have a non toll-free number for you to call and those 1-800 numbers don’t work while roaming. GVoice also works great over mobile data that I’m now having to provide with prepaid local sim cards. You must change a default setting in Voice to enable calls over mobile data instead of carrier only.
6. I have dual sim capability but not eSIM. Most iphones and pixel phones do have eSIM feature though. No need to wait for Fi’s physical sim if you can use the eSIM option. This MAY be a way to sign up after you arrive as well but good luck.
7. Now that I’m cutoff of roaming data I have changed to Fi’s cheapest plan that charges by the gig but I have no worries as they still won’t let me data roam to use any of it up so for 2 lines I pay 35/mth for the privilege to txt all I want and still make and accept traditional calls. I do this mainly for verification texts that come from online login verifications. Do note that Google Voice can accept txt messages from people but it will not work with banks and many others or any txt you get from those 5 digit numbers they send from (called short codes).
8. Google Fi gets cheaper with more lines on the plan. Max savings reached with 4 lines and a max of 7 lines per plan. All lines must be on same service level. You can upgrade plans anytime and they prorate the costs but when they cut you off of data in 3 months and you want to downgrade that is tied to your monthly cycle data so we paid high premiums for an additional 3 weeks without being able to have any data we were paying for.
9. The neatest feature with the premium plan is that you can order “data only” sims that are linked to the same bucket of data your phone gets. Up to 4 data sims per line. This allows you to put sim cards in other devices like your kids’ hand-me-down phones, hotspots, tablets, etc… There’s no additional cost and it just consumes data from the same bucket as the associated line. There’s also no calling or texting (no phone number) but you CAN use Google voice over them as a workaround. SIM must also be activated while physically in US. It is a special sim they ship only after you have officially signed up and requested it in the portal. You cannot get these sims at Best Buy. It’s a rare and great feature among mobile providers.

To sum up, the premium plan is great for the highest speeds and data caps while the cheapest plan works great to still get our texts and calls (at .20/minute). I very much recommend a dual SIM/eSim phone so you can still get cheap local prepaid SIM/eSIM cards for data at about a dollar/GB.

***Updates

1. One of our Fi sims has gone faulty while we’re traveling giving us very little options for a convenient recovery. While I can’t confirm a physical sim will activate remotely in Sept 2023 I can confirm that an eSIM from Fi was able to activate on a pixel handset while I was in Vietnam on local wifi.
2. It appears that Fi now tunnels our roaming data straight back to the US without a separate VPN service. Going to whatismyip.com confirms my location is identified as T-Mobile out of Chicago. This applies to hotspot clients as well.
3. As we’ve had a broken SIM we’ve realized that having our number ported to Fi allows us to use messages.google.com to send/receive texts and calls through both mobile and desktop sites. We no longer need our SIM active to have access to our numbers without any complicated forwarding schemes.