When looking at Japanese telecom products, you often see the phrase "unlimited data." However, some people experience a sudden drop in speed at some point during actual use. Why does it slow down if it's unlimited? The concept of FUP is hidden here.
What is FUP?
FUP stands for Fair Usage Policy. It is a regulation that sells plans as "unlimited" but restricts speeds once a certain amount of usage is exceeded.
- It does not block the total amount of data itself (which is why it is labeled "unlimited")
- However, if you use a lot in a single day or over a certain period, your speed will be throttled afterward
- In other words, it is often "unlimited in volume, conditional in speed"
This is why people who sign up looking only at the word "unlimited" are often caught off guard when things suddenly slow down at a certain point.
There Are Different Types of "Unlimited"
Even under the same "unlimited" label, conditions vary.
- Close to truly unlimited — FUP is lenient, and you will rarely hit the limit under normal usage
- Daily limit type — If you exceed a certain daily amount (e.g., a specific GB limit), your speed drops for the rest of the day and resets the next day
- Congestion-based type — Speeds are adjusted during peak hours when network traffic is high
The problem is that these conditions are rarely written in large letters on the front of advertisements; they are often tucked away in the small print of terms and conditions.
What You Should Check
Before signing a contract, instead of just looking at the word "unlimited," you should check the following:
- The threshold for speed throttling — How many GB per day, or is there virtually no limit?
- Speed after throttling — Is it still usable for maps, messaging, and basic web searches after slowing down?
- When the limit resets — Does it reset the next day, or does it last until the end of the month?
How to Choose Based on Your Usage
Unlimited is not always the right answer. It is better to look at your usage patterns first.
- If you have Wi-Fi at home — Your mobile data usage outside might only be for maps, messaging, and searching, meaning you might not need a large amount of data. In this case, you don't necessarily need an unlimited plan
- If you don't have Wi-Fi at home or rely solely on mobile data — If you handle video streaming and work on mobile data, your usage will be high, making an unlimited or high-capacity plan more advantageous
- Home Wi-Fi + Low-capacity SIM for outside — This combination is often the most cost-effective. Home Wi-Fi covers heavy data usage at home, while you use minimal data outside
In other words, instead of assuming "it's unlimited, so I'm safe," choosing based on where and how much you use can help you cut unnecessary costs.
How KEICALL Can Help
- Tailored combinations — We recommend configurations that fit your usage patterns, such as combining Home Wi-Fi with a mobile SIM
- Clear terms — We explain the speed and data limit conditions of each plan in English, preventing any unexpected slowdowns
- English consultation — Let us know your typical data usage, and we will help you choose the right plan
What matters more than the word "unlimited" is a setup that fits your usage patterns. If you are unsure which combination is right for you, feel free to contact us.
If you are curious about the best telecom setup for your usage, please contact us via KakaoTalk. We will assist you in English.