What to do about smartphone data overseas?

"What is the best way to handle smartphone data while traveling abroad?"

When I looked into it for my Florida trip (8 nights or more), there were so many options that I was confused at first...! But the more I researched, the more I realized that the best choice depends on the carrier you are currently contracted with, so I have summarized everything here!

📱 There are mainly 4 ways to use a smartphone abroad

① International Roaming (using your current contract as is)
② eSIM (adding a local SIM while still in Japan)
③ Local SIM card (purchased locally)
④ Pocket WiFi rental

To give you the conclusion, as of 2026, pocket WiFi rental is not cost-effective and is almost unnecessary. First, let's compare ① to ③ and choose the method that suits you!

🏆 Conclusion: Choosing based on your current carrier is the fastest way!

【Recommended communication methods by carrier】

📶 ① Thorough explanation of international roaming

For ahamo [The best for Florida trips!]

ahamo allows you to use data roaming in 91 countries and regions abroad without any additional fees.

Price: 0 yen additional
Data amount: Up to 30GB per month (combined with domestic usage)

Pros

• No additional fees or application required at all

• Just turn on data roaming after arriving locally

• Tethering can also be used for free without any application

⚠️ Points to note

• Regardless of data usage, speed will be restricted from the 15th day and will not be lifted until you return to Japan, so be careful if traveling for 8 nights or more

• If you watch a lot of videos, you might consume the 30GB quickly

💡 For long-term stays exceeding 15 days, using it in combination with an eSIM is recommended!

For Rakuten Mobile

Price: 0 yen additional (up to 2GB)
Rakuten Mobile allows international data communication up to 2GB without any application or additional fees.

Pros

• No additional cost up to 2GB

• You can make calls for free using the Rakuten Link app

⚠️ Points to note

• Speed is restricted (128kbps) after exceeding 2GB

• 2GB is quite unreliable for a Florida trip of 8 nights or more

• Excess data can be added at 500 yen per 1GB

💡 For Rakuten Mobile users, combining it with an eSIM is a practical choice!

For SoftBank users [The best for trips to the US!]

With a service called "America Hodai," you can use calls and data communication in the US mainland, Hawaii, and other covered areas for free (included in the plan price) without needing to apply in advance.

Cost: 0 yen extra
Data: Unlimited

Pros

• Unlimited data + free calls is an overwhelming advantage not found in other companies

• The best plan for trips to the US

⚠️ Points to note

• Not applicable in countries other than the US

• Limited to SoftBank contract holders

📲 ② What is an eSIM? How to choose and points to note

The biggest feature of eSIM
You can activate it on the same day just by scanning a QR code, and you can use the internet immediately after arriving at your destination. Unlike a physical SIM, there is no worry about loss or damage, and it is easy to save multiple plans on your device and switch between them.

Things to check before using an eSIM

① Check if your smartphone is eSIM compatible
Almost all iPhone XS and later models and the latest Android models are compatible. You can check from Settings > General > About.

② Check if the SIM lock is unlocked
Smartphones purchased after October 2021 are generally SIM-lock free. For models from before that, please check.

Recommended eSIMs for Florida trips (8 nights or more)

It is a good idea to consider whether you will use your phone as much as you do normally at your travel destination, after understanding how much you usually use the internet on your smartphone. If you use videos and social media every day, please also consider an unlimited data plan.

Estimated data amount for 8 nights or more in Florida

• Maps, social media, and photos only: approx. 3–5 GB

• Watching videos frequently: approx. 10–20 GB

• Full use of WDW app (My Disney Experience): approx. 5–10 GB

💡 At theme parks, you will use more data than expected for app maps, checking wait times, and uploading photos. We recommend a plan with plenty of data!

🆚 Summary of communication methods

Using ahamo → International roaming is fine as is (up to 8 nights)
No extra cost. However, be aware of speed restrictions if staying over 15 days.

Using Rakuten Mobile → We recommend purchasing a separate eSIM
2GB is likely insufficient for stays longer than 8 nights.

Using SoftBank → 'America Hodai' (Unlimited America) is the best
No extra cost for unlimited data and free calls in the US.

docomo/au/others → We recommend purchasing an eSIM
International roaming tends to be expensive, costing from 980 yen per day.

💡 In our case

We are currently checking our current carrier contracts to determine the best method! We will share which method we actually chose and our impressions of using it in our Florida travelogue😊

✅ Pre-travel checklist

• [ ] Check the international roaming rates of your current carrier

• [ ] Check if your smartphone is eSIM compatible

• [ ] Check if your SIM lock has been removed

• [ ] If canceling your Japanese SIM, change Wise two-step verification to app-based authentication (Super important!)

• [ ] Decide on and purchase a data communication method

• [ ] Check how to set up 'Data Roaming' before traveling

Summary

To summarize the points for mobile communication abroad...

• ahamo is the best with 30GB at no extra cost and no application required (However, be careful if staying over 15 days)

• SoftBank's 'America Hodai' is the best for travel to the US

• Rakuten Mobile is best combined with an eSIM

• For other carriers, purchasing an eSIM is the best value

• Pocket WiFi rental is almost unnecessary as of 2026

• If you are canceling your Japanese SIM, don't forget to change your Wise authentication settings!

I will reveal all the results of actually using it in Florida in my Florida travelogue😊

Head to the next article for recommended eSIM comparisons👇
[Florida Honeymoon] Recommended in the US4 eSIMsto choose from| Also explaining communication solutions for 2 people with different carriers

I've also compiled other useful travel information in a magazine!