ONE BANK Complete Guide
AI Budgeting × Visa Prepaid Card × Utility Payments
The all-in-one financial tool for household budget management in Japan
What is ONE BANK?
ONE BANK (formerly B/43) is an AI budgeting app combined with a Visa prepaid card, operated by SmartBank, Inc. Simply load your monthly budget onto the prepaid card and spend — all transactions are reflected in the app in real-time, automatically creating your household ledger with zero manual entry.
Rebranded from B/43 to ONE BANK in March 2025, it introduced an AI assistant called “Wan-Ban” that learns your spending habits and proactively suggests ways to save. The goal is to build a one-stop financial platform covering expense tracking, budget improvement, and wealth building.
3 Card Types
ONE BANK offers three card types for different use cases, all manageable within a single app.
My Card (Personal)
The standard card for personal expense management and daily spending. Available as virtual (instant) or physical card. Supports the “Atobari Charge” buy-now-pay-later feature.
Magnetic: Free ｜ IC Chip: ¥500Pair Card (Couples)
One account, two cards — share balance and transaction history with your partner. No marriage required — cohabiting couples can apply. Say goodbye to splitting bills.
Magnetic: Free ｜ IC Chip: ¥900/cardJunior Card (Kids)
Applied by parents, usable by children even without a smartphone. Perfect as a first card for teaching money management. Parents can monitor transactions in real-time via the app.
IC Chip: ¥900 (monthly fee currently free)IC chip cards support Visa contactless payments for easier in-store use. Virtual cards are sufficient for online-only usage. Since November 2025, ONE BANK supports Google Pay, enabling Visa contactless payments even with virtual or magnetic cards.
Top-Up Methods
ONE BANK supports various top-up methods, most of which are fee-free:
| Method | Fee | Notes |
|---|---|---|
| Bank Transfer | Free | Recommended! One-tap after setup |
| Credit/Debit Card | Free | Visa / Mastercard / JCB / AMEX |
| Seven Bank ATM | Free | At any 7-Eleven nationwide |
| Convenience Stores | Free | Lawson / FamilyMart / MiniStop, etc. |
| あとばらいチャージ | Fee applies | Buy now, pay by end of next month |
Funds loaded via bank transfer, ATM, or convenience stores can be withdrawn at Seven Bank ATMs (¥220 fee). However, funds loaded via credit card or Atobari Charge cannot be withdrawn.
Key Features
🤖 AI Assistant “Wan-Ban”
Launched alongside the March 2025 rebrand. This AI assistant learns your spending habits and proactively suggests savings. The “AI Spending Checker” gamifies expense categorization so the AI understands your money values. Choose from three character personalities for financial consultations.
📊 Real-Time Tracking & Budget Management
After paying with your ONE BANK card, transaction details are instantly pushed to your phone and automatically recorded — zero manual input needed. The app visually compares your current spending pace against last month and your budget, making overspending instantly visible.
🏦 Bank & Credit Card Linking
Beyond prepaid card transactions, you can link bank accounts and credit cards to consolidate all spending in one app. Free plan: 1 bank account; Plus members: unlimited.
📸 AI Receipt Scanning
For cash payments, simply scan receipts for automatic recording. Official accuracy exceeds 90.4%, requiring almost no manual corrections. Free: 20/month; Plus: 100/month.
💼 Pocket Feature
Divide your balance into purpose-specific “Pockets” — a digital version of the envelope budgeting method. Money in pockets cannot be spent until you manually move it back. Free: up to 3 pockets; Plus: up to 13.
💳 Atobari Charge (Buy Now, Pay Later)
For urgent needs, load up to ¥50,000 now and pay anytime before the end of the following month. Fees apply based on the amount. A personal loan service “My Pace Pay” was added in June 2025.
🔥 Killer Feature: Utility Bill Payments
This is ONE BANK’s biggest differentiator. Most prepaid cards (Kyash, Vandle Card, etc.) cannot handle recurring monthly payments, but ONE BANK supports most utility bills and subscriptions:
✅ Confirmed compatible payments:
⚡ Electricity (TEPCO, Kansai Electric, etc.) ／ 🔥 Gas ／ 💧 Water
📱 Mobile phone bills (docomo, au, SoftBank, Rakuten Mobile, etc.)
🎬 Subscriptions (Netflix, Amazon Prime, Spotify, etc.)
📺 NHK fees ／ 🏥 Some insurance premiums
🎮 App Store / Google Play in-app purchases
Pay mobile bills with ONE BANK → use carrier billing to top up PayPay/d-barai. This creates a high-reward credit card → ONE BANK → mobile bill → QR payment multi-layer cashback chain.
Gas stations, some hotels (post-payment type), highway tolls, and some e-money top-ups (Rakuten Edy, nanaco, etc.) are not supported.
Cashback Route Strategies
ONE BANK itself offers no purchase rewards, but it excels as the “exit point” for point-earning payment routes. Top up ONE BANK with a high-reward credit card, then use ONE BANK to pay utilities and subscriptions to earn indirect cashback.
📍 Route 1: IDARE Exit
📍 Route 2: Carrier Billing Expansion
📍 Route 3: Wesmo! In-Store 0.5% Reward
Comparison with Other Prepaid Cards
| Feature | ワンバンク | Kyash | IDARE | バンドルカード |
|---|---|---|---|---|
| Purchase Rewards | None | 0.2% | None (2% annual on balance) | None |
| Utility Payments | ✅ Most supported | ❌ | ❌ | ❌ |
| Budgeting App | ✅ AI Budgeting | Basic history | None | Basic history |
| ペアカード | ✅ | Shared account | ❌ | ❌ |
| Kids Card | ✅ | ❌ | ❌ | ❌ |
| Apple Pay | ❌ | ✅（QUICPay） | ❌ | ❌ |
| Google Pay | ✅ | ✅ | ❌ | ✅ |
| BNPL Feature | ✅ (up to ¥50k) | ❌ | ❌ | ✅（ポチっとチャージ） |
| Balance Limit | ¥1M | ¥1M | ¥1M | ¥1M (Real+) |
| Fraud Protection | Up to ¥100k | Yes (conditions) | Yes (conditions) | None |
ワンバンク最大优势是公共费用支付 + AI家计簿 + ペアカード三合一。如果你需要一张能支付水电煤气和手机费的预付卡，或者需要和伴侣共同管理家庭支出，ワンバンク是目前的最佳选择。搭配三井住友NL等High-Reward CC充值，可以在公共费用上也获得积分返还。
Free vs ONE BANK Plus
| Feature | Free | Plus（月额480日元） |
|---|---|---|
| Bank/Card Linking | 1 bank + 1 card | Unlimited |
| Pockets | Up to 3 | Up to 13 |
| AI Receipt Scan | 20/month | 100/month |
| Historical Data | Past 1 year | 1年以上 |
| Exclusive Card Design | ❌ | ✅ (Black/Marble) |
| Free IC Chip Card | ❌ (¥500) | ✅ (1 free) |
| CSV Export | ❌ | ✅ |
| Custom Categories | ❌ | ✅ |
The annual plan is ¥4,800 (¥400/month equivalent, saving 2 months). Minimum commitment is 2 months with early cancellation fees. The free plan is sufficient if you only use ONE BANK as a payment route exit. Consider Plus if you want to manage multiple bank accounts and credit cards in one place.
Pros & Cons
✅ Pros
- Supports utility bills & subscriptions
- AI budgeting with auto-tracking
- Pair Card — no marriage required
- Multiple free top-up methods
- Google Pay supported
- 3D Secure compatible
- Best exit point for IDARE
- Fraud protection up to ¥100k
❌ Cons
- No purchase rewards
- No Apple Pay support
- Not usable at gas stations/hotels
- CC-loaded funds cannot be withdrawn
- Plus requires 2-month minimum
- BNPL charges fees
How to Register (Get ¥300 Bonus)
Sign up with a referral code and top up ¥1,000+ to receive a ¥300 balance bonus. The code can only be entered during registration — it cannot be added later.
Download ONE BANK from App Store/Google Play. Tap “If you have a referral code” to enter it.
Select My Card, Pair Card, or Junior Card. Skip physical card if you only need virtual.
Verify with your residence card or driver’s license. After approval, BNPL and your own referral code become available.
Top up via bank transfer, credit card, or convenience store. The ¥300 bonus is credited instantly after loading.
vs Budgeting Apps
ONE BANK occupies a unique position as both a prepaid card and budgeting app. Here’s how it compares to dedicated budgeting apps:
| Feature | ワンバンク | MoneyForward ME | Zaim |
|---|---|---|---|
| Monthly Cost | Free (Plus ¥480) | Free (Paid ¥540~) | Free (Paid ¥440~) |
| Prepaid Card | ✅ Visa Prepaid | ❌ | ❌ |
| Free Linking | 1 bank + 1 card | 4 | Unlimited |
| Budget Control | ✅ + Prepaid enforced | ✅ | ✅ |
| AI Features | AI analysis & advice | Basic categorization | Basic categorization |
| Best For | Controlling spending via prepaid | Comprehensive asset tracking | Detailed spending analysis |
What makes ONE BANK unique: spending IS bookkeeping. No need to open a budgeting app later and manually log transactions — the moment you pay with the card, it’s recorded. For people who can never stick with a budget app, this passive tracking approach might be the best solution.