After I purchased an international data plan and installed the eSIM, when will my data plan start?
You can start using it whenever. Your plan will expire 30 days after plan purchase.
If you have dual sim, you should see one of both of your data plans
If you are using an iPhone, you should see one or both of your cellular plans in your status bar when you open the control center. You should also be able to see all your plans when you go to Settings > Cellular or Settings > Mobile Data. Learn more about dual sim check this Apple article.
If your cellular is not showing up or not working
If you have installed eSIM and find that you have no signal at your destination country, please follow the below guide on how to self troubleshoot.
Make sure your phone is unlocked, check this article for how to unlock your device
Turn your phone off and on again
Make sure airplane mode is off
Make sure your data roaming is on for the intended plan
Is service available in the country you're visiting? Check our country list
Make sure you've set your eSIM, APN settings, and cellular settings correctly
Are you experiencing slow data speed?
If you exceed the data-usage limits of your international data plan, you might run out of data or notice slower network speeds. To check data usage, open Settings and tap Cellular, or Cellular Data, or Mobile Data. Then look under the Cellular Data heading.
Data speeds for your US Mobile international eSIM are generally dependent on factors like the local networks' coverage, congestion, and prioritization.