Prepaid SIMs for the First Month
A prepaid SIM Japan newcomers can buy before they have local banking is the standard bridge for the first month.12 It provides data and, on voice plans, a real Japanese number while the new arrival waits for a bank account or credit card.3
Procedures, fees, and requirements can change. Confirm current details at each provider's official site (Mobal, Sakura Mobile, and GTN Mobile).
Overview
This guide covers the prepaid bridge for new arrivals: why a normal contract is out of reach in week one, how Mobal, Sakura Mobile, and GTN Mobile compare, what the first month typically costs, how to buy at the airport, and when to switch to a normal contract.45 It applies to mid- to long-term arrivals who lack a Japanese bank account or Japanese-issued credit card, including applicants ordering from abroad before they fly.61
The whole first month follows one simple arc: land connected, live on prepaid while banking gets sorted, then move to a cheaper contract.
Why Prepaid First: The New-Arrival Gap
Most normal mobile contracts ask for a bundle a new arrival cannot yet produce: a residence card (在留カード (zairyū kādo, "residence card")), a registered Japanese address, and a Japanese credit card or bank account for monthly billing.5 Standard domestic screening is strict on these points, so a week-one online application commonly fails.4
Prepaid products built for foreign residents waive exactly that bundle. Mobal long-term SIMs carry no contract and cancel anytime, with English support throughout.6 Sakura Mobile signs new residents up in English with no Japanese bank account, accepting international cards.2 GTN Mobile prepaid data-only plans need only a passport to apply, with no initial processing fee and no residency-expiry requirement.3
What a normal contract asks for
A normal contract pairs identity with a domestic payment method. The applicant shows a residence card and a registered address, then pays by Japanese credit card or bank auto-debit.5 Each element takes days or weeks to arrange after landing, which is why the first month needs a different product.4
| Requirement | New-arrival status |
|---|---|
| Residence card | Issued at arrival or ward registration, but address matching takes time5 |
| Japanese address | Settled only after moving in and registering5 |
| Japanese card or bank account | Commonly weeks away; some banks apply extra scrutiny to new residents5 |
What prepaid waives
Prepaid waives the domestic payment requirement first and the tenure requirement second. Mobal takes debit, credit, or PayPal with no Japanese-issued card at signup.6 Sakura Mobile accepts any international credit or debit card, all in English.2 GTN Mobile goes further on payment flexibility across its services, accepting credit card, bank auto-deduction, or convenience-store cash payment.7
The Three Foreign-Resident Options Compared
All three providers serve the same gap with different strengths. Mobal leads on pre-arrival readiness, Sakura Mobile on docomo-network monthly simplicity, and GTN Mobile on in-person multilingual support with bundled life services.4
Mobal
Mobal is a UK-based provider focused on foreign residents and arrivals, selling Voice-Only and Voice+Data long-term SIMs and eSIMs with a real 070, 080, or 090 Japanese number (as of 2026-07-27; confirm current figures with Mobal).61 Monthly Voice+Data fees run ¥1,650 for 1GB, ¥3,190 for 5GB, ¥3,630 for 10GB, and ¥4,378 for 30GB (as of 2026-07-27).1 The Voice-Only plan costs ¥1,430 per month (as of 2026-09-06).6
A one-time SIM issuance fee of ¥3,300 for a physical SIM or ¥3,960 for an eSIM applies on top (as of 2026-07-27).1 Outgoing domestic calls bill at about ¥44 per minute while incoming calls and incoming SMS stay free (as of 2026-07-27).61
Airport and counter pickup needs only a passport, and international shipping needs home-country ID plus address proof. Domestic delivery inside Japan instead requires a residence card, so a cardless arrival who picks home delivery gets stuck (as of 2026-07-27).1
Sakura Mobile
Sakura Mobile is the new-arrival and frequent-traveler friendly option on the docomo network, with month-to-month Voice+Data SIMs and eSIMs and no lock-in (as of 2026-09-06; confirm current figures with Sakura Mobile).2 Voice+Data starts at ¥2,980 per month excluding tax (¥3,278 including tax), and data-only starts at ¥2,480 excluding tax (¥2,728 including tax) (as of 2026-09-06).2 Voice plans include a Japanese phone number, data rollover, and hotspot tethering (as of 2026-09-06).2
Signup, plan changes, and cancellation all run in English online, with airport pickup and delivery available.2 Travel prepaid data-only SIMs for the shortest stays start from ¥3,500 excluding tax (¥3,850 including tax) (as of 2026-09-06).8
GTN Mobile
GTN Mobile is the foreign-resident specialist run by グローバルトラストネットワークス (Gurōbaru Torasuto Nettowākusu, "Global Trust Networks"), pairing SIMs with multilingual support and bundled life services such as rent guarantees and a foreigner-oriented credit card.74 Its prepaid range splits into data-only plans for 7, 30, or 90 days and Data+Voice plans for 30, 60, or 90 days (as of 2026-09-06; confirm current figures with GTN Mobile).3
Data-only pricing runs ¥3,000 for 10GB over 30 days, ¥3,000 for 30GB over 7 days, ¥5,000 for 50GB over 30 days, and ¥10,000 for 135GB over 90 days, all tax included with no initial fee (as of 2026-09-06).3 Past the cap the speed drops to 200kbps with no top-up available (as of 2026-09-06).3 Data-only plans need only a passport to apply and run on the NTT DOCOMO 4G (LTE) network as eSIM or multi-cut physical SIM.3
Data+Voice pricing runs ¥8,250 for 10GB over 30 days and ¥12,100 for 30GB over 30 days, with 60-day and 90-day tiers above (as of 2026-09-06).3 These plans are in-store purchase only, at the Shin-Okubo Tokyo store, the Osaka store, the Seoul branch, and the Central Japan International Airport counter, and they require a passport plus a second government document showing name and address.3
Payment is by credit card only.3 Domestic calls bill at ¥22 per 30 seconds including tax, outgoing domestic SMS at ¥3.3 to ¥33 per message, and incoming SMS is free (as of 2026-09-06).3
Prices and What You Get
The typical first-month prepaid tier with data plus minutes lands between ¥3,000 and ¥5,000 per month (as of 2026-07-27 for Mobal figures and 2026-09-06 for Sakura Mobile and GTN Mobile figures; confirm current figures with each provider).123 That band buys a usable 5GB to 10GB with a real number at Mobal or Sakura Mobile, or a 10GB to 50GB data-only block at GTN Mobile.123
Typical prepaid tier
| Item | Amount | As of | Notes |
|---|---|---|---|
| Mobal Voice+Data 5GB per month | ¥3,190 | 2026-07-271 | Real 070/080/090 number included |
| Mobal Voice+Data 10GB per month | ¥3,630 | 2026-07-271 | Plus one-time issuance fee |
| Sakura Mobile Voice+Data from | ¥3,278 incl. tax | 2026-09-062 | Docomo network, rollover included |
| GTN prepaid data-only 10GB/30 days | ¥3,000 incl. tax | 2026-09-063 | Passport only, no phone number |
| GTN prepaid data-only 50GB/30 days | ¥5,000 incl. tax | 2026-09-063 | Throttled to 200kbps past cap |
| GTN prepaid Data+Voice 10GB/30 days | ¥8,250 incl. tax | 2026-09-063 | In-store purchase only |
Buying at the Airport on Arrival
Day-one connectivity comes from three channels: a staffed brand counter, a SIM vending machine, or a pre-ordered pickup. Pre-ordering before flying beats all three on certainty.61
Counters, vending machines, and pre-order pickup
Mobal holds free same-day pickup at Haneda Airport Terminal 3 (JAL-ABC arrival counter, open 4am to 1am daily), Narita Terminal 1 and Terminal 2, Kansai, Chubu, Fukuoka, and city counters, needing only the order confirmation and a passport.6 JAL ABC counters at Narita Terminals 1 and 2 and Haneda Terminal 3 also sell prepaid SIM and eSIM products directly on arrival.9 SIM vending machines at major airports cover the walk-up fallback when counters are closed, and B Mobile visitor SIMs at electronics retailers such as Yodobashi and Bic Camera cover the 30-day data-only fallback after leaving the airport (limitation: retailer and vending-machine details trace to secondary sources).45
Mobal ships SIMs worldwide for free, so an arrival who orders a week out can land with the SIM already in the phone.61 That single step removes the arrival-day queue entirely.
Switching to a Normal Contract After 1 to 3 Months
Prepaid is a bridge, not a home. Once banking exists, cheaper domestic plans open and the bridge has done its job.45
When to switch
The switching trigger is the banking milestone: a Japanese bank account or credit card in hand. Practitioner guidance consistently describes 1 to 3 months on the bridge before that move, which is timing guidance rather than any provider rule.4 GTN prepaid Data+Voice converts directly to the GTN Mobile Eazy long-term plan on additional documents, while Mobal long-term SIMs simply continue as ongoing monthly contracts with no termination fee.36
Keeping your number
Check number-portability terms before switching so the first-month number survives the move. The full porting mechanics belong to the sibling number-portability article and sit outside this guide's scope.4 One caution survives here: some GTN Mobile users report difficulty porting a number away to another carrier without an intermediate step, though that stays at the user-report level from early 2026 rather than confirmed provider terms.4
Good to know
Data-only SIMs cannot verify bank and payment apps
Bank account applications, PayPay, LINE, and most Japanese apps send SMS verification codes only to a real 070, 080, or 090 number.1 Data-only SIMs and VoIP 050 numbers are rejected at that step. Any arrival who needs banking in week one needs a voice plan, not the cheapest data block.1
Order or reserve before you fly when you need a number on landing
A working number at touchdown takes advance action. Mobal ships worldwide for free or holds SIMs at airport counters, while walk-up arrivals depend on counter hours and vending-machine stock.61 Reserve the pickup date at checkout or ship early to remove arrival-day uncertainty.
Prepaid voice rates and top-up limits surprise heavy callers
Per-minute and per-message billing adds up fast for anyone who calls a lot. Mobal outgoing calls bill around ¥44 per minute (as of 2026-07-27), and GTN prepaid Data+Voice bills ¥22 per 30 seconds with SMS on top (as of 2026-09-06).13 GTN prepaid data-only cannot be topped up at all and throttles to 200kbps past the cap (as of 2026-09-06).3
Heavy callers should size the voice tier before buying, not after.
See also
- Bank Account in Japan for Foreigners: The Six-Month Rule
- Internet and TV: Utility Setup Overview
- Big Three Carriers vs. MVNO Sub-Brands
- Number Portability (MNP) Procedure
- eSIM and Multi-SIM Setups in Japan
- Mobile Plan Considerations for Foreign Residents