Call Charge Basics
What you pay for calls on a smartphone varies enormously with the plan you are signed up to. Start with the basics.
- Pay per use: you pay for the time you spend on calls, at a rate that depends on your plan
- 5-minute unlimited: calls of up to 5 minutes each are free. Anything beyond that is billed per use
- Fully unlimited: domestic calls are free with no time limit
Check your contract to see which plan you are on. It is easy to look up in your carrier's app (My docomo, My au, My SoftBank).
If you use your phone without knowing how call charges work, an unexpectedly large bill can arrive at the end of the month. Be especially careful if you are not on an unlimited plan: pay-per-use charges climb in proportion to the time you spend talking, so one long call after another and the bill swells fast. If you spend a lot of time on calls each month, it is worth considering an unlimited plan.
Numbers That Cost Money Even on an Unlimited Plan
Assume "I am on unlimited, so I am fine" and a bill you did not expect can still turn up. The numbers below fall outside almost every unlimited plan. Knowing what the first digits of a phone number mean makes it easier to tell the different types apart.
0570 (Navi Dial)
This is the number range companies commonly use for their support lines. It is excluded from unlimited plans, and you pay call charges based on how long you are connected. With NTT Docomo Business's Navi Dial, calling from a mobile phone costs 11 yen (tax included, as of August 2026) per 20 seconds - roughly 99 yen for three minutes, and around 990 yen if you are kept waiting for thirty.
How to save: look on the company's official website for a number that is not 0570 (one starting with 03 or 06). Many companies publish a landline number alongside the 0570 one. Searching for the company name together with "general number" or with "03" will sometimes turn one up. An ordinary number is covered by your unlimited plan, so this can cut your call costs dramatically.
International Calls
Calls to numbers outside Japan (numbers beginning with +) are excluded from unlimited plans. International call rates vary with the country you are calling and the route the call takes, and they run far higher than calls within Japan.
How to save: for calls with people abroad, use internet calling through LINE, FaceTime or a similar app. On Wi-Fi there is no call charge and no data allowance to worry about.
0990 (the Former Premium Rate Information Service)
Numbers beginning with 0990 were used for Dial Q2, a service that added an information fee on top of the call charge, and it closed in February 2014. Today, the risk of running up a large bill by returning a call you do not recognise lies with international numbers.
Satellite Phones
Calls to satellite phones are also outside unlimited plans. Dialling one from an ordinary mobile phone costs far more than a typical call within Japan.
Are LINE Calls Really Free?
LINE calls carry no call charge, but they do use mobile data. On Wi-Fi they are completely free; without Wi-Fi they eat into your data allowance.
- Voice calls: the data they use is small, and with normal usage there is little to worry about
- Video calls: sending video is far heavier than voice, so Wi-Fi is the safer choice for long calls
Once you hit your data cap your speed is throttled, and the sound quality of LINE calls drops with it. If you tend to run short of data towards the end of the month, make a habit of taking video calls on Wi-Fi.
Besides LINE there are plenty of apps you can call on for free: FaceTime (between iPhones), Discord, WhatsApp and others. As long as the other person uses the same app, none of them charge for calls. Calling apps built on VoIP technology, used in the right situations, mean more calls that cost you nothing at all.
Saving With an 050 IP Phone Number
Using an 050 IP phone service can cut the cost of calling landlines dramatically. Some of these services set a lower per-minute rate than pay-per-use mobile charges, and the more often you call landlines, the more that gap shows.
An 050 number costs anywhere from nothing to a few hundred yen a month, and all you need is an app on your phone. If you often call shops or clinics, an 050 number is worth looking into. Be aware, though, that an 050 number cannot reach emergency numbers such as 110 and 119. In an emergency, call from a mobile or a landline.
Cutting the Monthly Bill Itself With a Low-Cost SIM
If you want to bring down not just call charges but the monthly fee itself, switching to a low-cost SIM (MVNO) is effective. They are designed to sit below the major carriers' plans on monthly fees, and the less data you use, the bigger the drop tends to be. With MNP (mobile number portability) you can switch while keeping the phone number you have now.
The monthly difference stacks up month after month, so it can matter more than anything you save on call charges. Having the basics of SIM cards straight makes the decision easier. Considered together with savings on call charges, it can cut your total communications spending sharply. Do note that low-cost SIMs can slow down during the lunch break and in the early evening, so if speed matters to you, keep the major carriers' online-only plans (ahamo, povo, LINEMO) on your list as well.
How to Check What You Are Spending on Calls
- Docomo: My docomo app, then Charges
- au: My au app, then Charges and data
- SoftBank: My SoftBank app, then Charges and payments
You can check partway through the month, so look in regularly and ask yourself how much you have spent so far. The itemised call record shows which numbers you called and for how long, which is where the clues to saving money are.
Summary
There are four points to saving on call charges. Look for an alternative landline number instead of a 0570 one. Use LINE for calls overseas. If you call landlines often, consider an 050 number. And know which numbers your own plan excludes. That alone prevents money going to waste.
Call charges are the kind of spending where simply knowing makes a large difference. It also pays to understand the pricing that goes with each type of number, such as the difference between 0120 and 0800. Talk at length on a number your unlimited plan excludes without realising it, and a single call can bring a bill far larger than you expect. Put the tips in this article into practice and use your phone wisely. Even just getting into the habit of checking your itemised call record each month makes wasted spending much easier to spot.