Daily Life Lessons · Mobile Phones
Be able to read your mobile phone bill by breaking it down into the basic charge, data allowance, call charges, options and device payment, check the conditions for discounts and the price after discounts end, and decide for yourself whether a plan suits the way you use your phone.
Your mobile phone bill is the total of the basic charge (data allowance), call charges, option fees, the device payment and so on. The "lowest price" in advertisements is often the amount you pay only if you meet every one of several discount conditions, so calculate your monthly total using only the conditions that apply to you. Also check the price after any limited-time discount ends.
First, check how much data you use each month on the member page or similar. People who often watch videos need very different amounts from people who mainly use email and maps. Cancel any options you are not using.
If you pay for the device in installments, it is billed every month separately from the service fee. If a program says "return the device and you won't have to pay the rest," check its conditions carefully.
携帯電話の 料金（りょうきん）は、いくつかの お金を 合わせた ものです。
- 基本料金（データの 量） - 電話の お金（通話料） - オプションの お金 - 電話（たんまつ）の 代金
広告の「いちばん 安い」料金は、割引（わりびき）の 条件が 全部 ある ときの 金額の ことが 多いです。自分に 合う 条件だけで 計算しましょう。割引が 終わった あとの 金額も 見ましょう。
毎月 どのくらい データを 使って いるか、会員（かいいん）ページで 確認しましょう。使わない オプションは やめましょう。
電話の 代金を 分割（ぶんかつ）で 払うと、毎月 別に 請求（せいきゅう）されます。
What should you be careful about with the "lowest price" in advertisements?
Calculate your monthly total using only the discount conditions that apply to you.
What should you check before signing up for a limited-time discount?
The price may go up when the discount ends. Also check the amount after it ends.
How can you find out how much data you need?
The amount of data you need varies greatly depending on how you use your phone. First check your own usage.
What happens if you pay for the device in installments?
Device installments are billed every month until they are paid off.
What should you do with options you are not using?
You keep paying every month for options you don't use. If you don't need them, cancel them.
Q. Where can I see the breakdown of my monthly bill?
A. With many mobile carriers, you can check the breakdown, such as the basic charge, call charges, options and device payment, on the member page or app. If you don't understand how to read it, ask the company you have a contract with.
Q. I make a lot of phone calls. What should I be careful about?
A. On plans without flat-rate calling, you pay call charges according to how long you talk. If you use the phone a lot, compare plans by the monthly total, including flat-rate calling options and so on.
Q. Someone called or texted me saying "You will definitely pay less than now."
A. Do not sign a contract on the spot or open links in text messages. Check the prices on the mobile carrier's official website or member page. If you are in trouble, you can call the consumer hotline "188" to consult a consumer affairs center (消費生活センター) or similar.
This practice tool asks questions in random order (it works when JavaScript is enabled). You can still read all the questions and explanations above without it.
Systems and procedures may differ depending on the city, ward, town or village where you live and on the time of year. Please check the latest information from your local government or the relevant organizations.
Content checked on: 2026-10-03
This page is a translation of the Japanese original. If the translation and the original differ, the Japanese version takes precedence. View the Japanese original