ADR-005: Payments partner at launch — direct scheme membership deferred¶


Status	Accepted
Date	2026-04-10
Deciders	CEO, CTO, Head of Payments
Affects repos	`bank-payments`

Status¶

Accepted — 2026-03-23

Context¶

Direct membership in payment schemes (NPP in AU, Payments NZ) requires significant infrastructure investment, regulatory approvals, and operational capability. At launch, transaction volumes do not justify this investment. A sponsor/partner model provides scheme access faster and with lower fixed cost.

Decision¶

At launch, use a payments partner for scheme access — Monoova or Cuscal for AU NPP access, a Payments NZ participant for NZ interbank payments. The integration layer is abstracted behind an internal payments API so the sponsor can be swapped or supplemented with direct membership without application changes. Direct scheme membership is a Phase 2 consideration once volumes justify the infrastructure.

Consequences¶

Positive - Faster time to market — no scheme membership approval process at launch - Lower fixed cost — no settlement infrastructure to build and operate - Flexibility — abstraction layer allows partner swap without app changes

Negative / trade-offs - Per-transaction fees to sponsor — margin compression at high volumes - Dependency on sponsor availability and SLAs - Some real-time payment features may be constrained by sponsor capabilities

Constraints this creates for bank-payments¶

All scheme interactions must go through the internal payments abstraction layer
No direct scheme API calls in business logic — only through the abstraction
Sponsor SLA must be monitored and included in availability calculations (NFR-020)
Target: domestic payment confirmation ≤ 5s p99 (NFR-025)

Principles alignment¶

Principle	Assessment	Notes
AP-001 KISS	✓	Simpler to integrate and operate than direct membership at launch
AP-006 Cost effective	✓	Avoids large fixed infrastructure cost; variable cost scales with volume
AP-007 Evolution	✓	Abstraction layer preserves option to move to direct membership
AP-009 Robust and serviceable	~	Adds external dependency; SLA monitoring required

Perspectives¶

Perspective	Assessment	Notes
Performance & Scalability	~	Sponsor latency limits; monitor against NFR-025
Strategy	✓	Standard neobank approach at launch; proven by multiple new entrants
Resilience & Availability	~	Sponsor is a single point of failure; contingency plan required
Integration	✓	Abstraction layer is the key; well-understood pattern
Cost	✓	Per-transaction pricing appropriate at startup volumes
Regulatory	✓	Sponsor manages scheme compliance; bank responsible for AML/CTF
Evolution	✓	Abstraction layer makes future migration low-risk

See perspectives.md for how to use these evaluation lenses.

Relevant viewpoints¶

System viewpoint — Payment abstraction layer; sponsor connectivity; scheme access
Operational viewpoint — Sponsor SLA monitoring; fallback procedures; reconciliation

See viewpoints.md for guidance on producing these viewpoints.

Signoff record¶

Date	Name	Role	Status
2026-04-10	Ross Millen	CTO	Approved
2026-04-10	Ross Millen	Head of Architecture	Approved
2026-04-10	Ross Millen	Head of Data	Approved

Capabilities¶

Capability	Description	Relationship
CAP-004	Instant NZ transfers (NPP / PayID equivalent)	enabled — NPP scheme access via Payments NZ participant
CAP-007	Scheduled & recurring payments	enabled — scheme access required for recurring payment execution
CAP-008	Bill payments & BPAY (AU)	enabled — AU scheme access via Monoova/Cuscal enables BPAY
CAP-009	Direct debit management	enabled — scheme access enables direct debit rail
CAP-042	Fee-free international transfers up to threshold	governed — fee structure depends on sponsor pricing model

ADR	Title	Relationship
ADR-015	Cross-border NZ/AU wallet and transfer design	cross-border transfers do not use the payments partner — internal journal entries

All ADRs Compiled 2026-05-22 from source/entities/adrs/ADR-005.yaml