Which rail should I pick?
Decision matrices for the recurring "what rail do I use for X?" question. Each section gives the answer per region, the why, and the gotcha.
"I want fastest finality for a B2C deposit"
Use case: customer is funding a wallet or buying crypto. You need the money final (not recallable) before releasing crypto.
| Region | Pick | Why | Watch out for |
|---|---|---|---|
| India | UPI | <5s, irrevocable, near-zero cost | Per-day caps; PSP dispute mechanism still exists |
| Brazil | PIX | <10s, 24×7 | MED reversal window (narrow but real) |
| UK | FPS via Open Banking | <2h finality | APP-fraud reimbursement liability (PSR 2024) |
| EU | SCT Inst | <10s | VoP mandatory Oct 2025; some banks still lag |
| US | RTP > FedNow | Final on confirmation | Sponsor-bank participation gates coverage |
| Mexico | SPEI | <30s, 24×7 | CLABE-only; QR (CoDi) optional |
| Nigeria | GIP (NIBSS) | <30s, dominant rail | SEC crypto-exchange registration required |
| South Africa | PayShap | <10s | FSCA CASP licensing for crypto |
| Kenya | M-Pesa Paybill/Till | Real-time wallet | Daily wallet caps |
| Singapore | PayNow | <5s | MAS DPT license |
| UAE | Aani | <5s, 24×7 | VARA / SCA crypto licensing |
| Global fallback | Stablecoin (USDC on L2 or Solana) | Seconds, deterministic cost | User must already hold the stablecoin |
"Cheapest cross-border payout to LATAM"
| Corridor | Pick | Why | Avoid |
|---|---|---|---|
| USD → BRL | USDC → local PIX payout via Bridge / Brale partner | 2–10 bps spread vs 50+ bps via SWIFT | SWIFT correspondent — opaque cuts |
| USD → MXN | USDC → SPEI via local IFPE partner | Near-zero local leg cost | SWIFT to MX bank |
| USD → ARS | USDT (Tron) ↔ local CVU | Argentina FX premium makes stablecoin dominant | Official FX channels (BCRA tax) |
| USD → COP | Stablecoin → PSE via local partner | PSE adds same-day settle | SWIFT (high cost, slow) |
| EUR → BRL | EURC or USDC → PIX | Skip the EUR-USD-BRL leg | Multi-leg correspondent |
"Stablecoin sandwich" pattern: fiat → stablecoin (on-chain bridge) → fiat. The on-chain leg replaces correspondent banking. Settlement compresses days → minutes; cost compresses 50–200 bps → 5–20 bps.
"Recurring subscriptions with mandate support"
Use case: SaaS subscription, monthly wallet top-up, dollar-cost-average crypto buy.
| Region | Pick | Mandate type | Pull semantics | Refund window |
|---|---|---|---|---|
| EU | SEPA Direct Debit | SDD CORE mandate (signed) | True pull | 8 weeks unconditional |
| UK | VRP (Open Banking) | Variable Recurring Payment | Push initiated by AISP-PISP | None (FPS finality) |
| UK (legacy) | BACS Direct Debit | DDIC indemnity | Pull | Indefinite indemnity |
| US | ACH debit | Nacha authorization (WEB/PPD) | Pull | 60 days consumer |
| US (instant-ish) | RTP RfP | Push, user approves each | Not true pull | None |
| India | UPI AutoPay | e-mandate (NPCI) | Variable up to limit | Per-mandate |
| Brazil | Pix Automático | Mandate (rolling out 2025) | Pull | TBD by BACEN |
| Card | Network Token (Visa, MC) | Stored credential | MIT (merchant-initiated) | Chargeback up to 120d |
"Irrevocable settlement, no chargeback risk"
Use case: you're accepting funds before releasing a high-value or irreversible good (crypto, gold, gambling chips).
| Rank | Rail | Why irrevocable | Caveat |
|---|---|---|---|
| 1 | UPI, PIX, FedNow, RTP, SCT Inst, FPS | Push-based instant rails with scheme-level finality | Fraud recall mechanisms still exist (MED in BR, APP-fraud rules in UK) |
| 2 | Fedwire / CHAPS / RTGS | Real-time gross settlement, irrevocable | Business hours; high cost |
| 3 | Stablecoin (post finality) | On-chain confirmation | Pre-finality reorgs (rare on Ethereum mainnet) |
| 4 | Same-Day ACH | NOT irrevocable | 60-day return window for consumer ACH |
| 5 | Card payment | NOT irrevocable | ~120 days chargeback window |
"Unbanked / cash-rich market on-ramp"
| Market | Pick | UX |
|---|---|---|
| Brazil | Boleto | Print or QR; pay at lottery agent or bank |
| Mexico | OXXO Pay | Cash voucher at OXXO convenience store |
| Egypt | Fawry | Agent-network voucher |
| Indonesia | Virtual account + minimarket cash (Alfamart, Indomaret) | VA code paid in cash at counter |
| Kenya | M-Pesa via agent | Cash deposit to M-Pesa wallet |
| Nigeria | USSD bank / agent banking | Feature-phone USSD code |
| Philippines | GCash / Maya cash-in at 7-Eleven | Cash-to-wallet |
"High-value B2B (institutional treasury, OTC)"
| Region | Pick | Cap | Cost |
|---|---|---|---|
| US | Fedwire | None | $15–$40 |
| US (instant) | RTP | $10M (raised 2025) | $0.045 + bank markup |
| UK | CHAPS | None | £15–£35 |
| EU | TARGET2 / T2 / SCT Inst | €100K (SCT Inst); none (T2) | Negotiated |
| India | RTGS | None | ₹25–₹50 |
| Brazil | PIX or TED | None (bank-set) | Low |
| Cross-border | Stablecoin (USDC) to licensed counterparty | None | Gas only |
"Need to issue refunds cleanly"
| Original rail | Refund mechanism | Cost | UX |
|---|---|---|---|
| Card | Refund to original PAN via acquirer | Sometimes interchange-credited | Best (issuer credits within days) |
| SEPA | SCT in reverse (push to IBAN) | €0.05–€0.30 | Need IBAN |
| FPS | FPS in reverse | £0.01–£0.10 | Needs sort code + account |
| UPI | UPI refund (UPI ID stored) | Free | Excellent |
| PIX | PIX refund (devolução) | Free | Excellent |
| ACH | ACH credit OR cancel pending debit | $0.20–$1.50 | 1–3 days |
| Wire | Manual wire back (recall = beneficiary consent) | $15–$40 | Painful |
| Stablecoin | On-chain reverse send (different tx) | Gas | Wallet address required |
Chargeback / reversibility risk axis
Treat reversibility risk as a continuous spectrum, not binary. For crypto on-ramps, where the asset is irretrievably handed to the user, this is the single most important axis.
| Risk level | Rails | Recommended posture for crypto on-ramp |
|---|---|---|
| Highest | Card (Visa, MC, Amex), SEPA Direct Debit | 3DS2 + ID match + velocity limits + delayed crypto release |
| High | ACH (US), BACS (UK) | 5-day crypto hold or insure the float |
| Medium | SCT (non-instant), Boleto unpaid risk | Hold for inbound clearing |
| Low | FPS, PIX, UPI, SCT Inst, RTP, FedNow, SPEI, GIP, Aani, PayNow, PromptPay, etc. | Release on confirmation; monitor fraud-recall mechanisms |
| None | Fedwire, CHAPS, RTGS, post-finality stablecoin | Release immediately |
Selector matrix
If you only remember one table, remember this:
| Need | Best US | Best EU | Best UK | Best IN | Best BR | Global cross-border |
|---|---|---|---|---|---|---|
| Fast irrevocable deposit | RTP / FedNow | SCT Inst | FPS via OB | UPI | PIX | USDC on L2/Solana |
| Recurring / mandate | ACH debit | SDD | VRP / BACS DD | UPI AutoPay | Pix Automático (2025) | Network Token |
| Cheap payout | ACH | SCT | FPS | NEFT / UPI | PIX | Stablecoin |
| High-value | Fedwire | T2 | CHAPS | RTGS | PIX / TED | SWIFT or stablecoin |
| Unbanked | Cash-at-7-11 (PayNearMe) | n/a | n/a | n/a | Boleto | Stablecoin via local cash agent |
| Refund clean | Card > ACH credit | SCT | FPS | UPI | PIX devolução | Stablecoin reverse |