PAYMENTS SIGNAL REFERENCE ARCHITECTURE · SYNTHETIC / TRAINING ONLY
Instant-payment processing, settlement, timeout, and 24×7 operations architecture
Makes the service clock, bounded controls, funded settlement, receiver response, late-status ordering, and 24×7 recovery responsibilities explicit.
Payments Signal reference architecture v1 · reviewed 2026-07-23
Reference architecture—not a scheme mandate. The blueprint uses one time-budgeted route to explain common instant-payment responsibilities. Exact execution clocks, response codes, prefunding, finality, return rights, maintenance, and participant obligations differ by rail and current rulebook.
Components
Payer channel and confirmation
Captures an always-available payment intent and tells the payer what is known within a short time budget.
- Kind
- channel
- Owner
- Digital channel
- Responsibilities
- Authenticate and confirm the payer's intent
- Show a truthful pending, rejected, or completed outcome
- Inputs
- Payer, payee, amount, account or proxy, confirmation
- Outputs
- Idempotent instant-payment request
- Controls
- Authentication
- Entitlement
- Confirmation
- Client idempotency key
- Failure modes
- Repeated tap
- Channel timeout
- Stale payee verification
- Recovery
- Enquire using the same reference
- Do not create a second payment while outcome is unknown
- Non-functional requirements
- Durable correlation through stable business and technical identifiers
- Capacity and availability matched to the service-level objective
- Auditable state changes, configuration, and operator actions
Sending instant-payment engine
Completes validation, controls, posting intent, routing, and submission inside the service time budget.
- Kind
- application
- Owner
- Sending payment product and technology
- Responsibilities
- Validate and route quickly
- Coordinate screening and fraud decisions
- Reserve or debit under policy
- Inputs
- Confirmed instant-payment request
- Reference and risk data
- Outputs
- Network instruction and durable pending state
- Controls
- Duplicate detection
- Account and funds check
- Time-budget enforcement
- Failure modes
- Control exceeds time budget
- Unknown network outcome
- Internal posting lag
- Recovery
- Stop or time out under the rail rules
- Reconcile before retry
- Release reservations from proven outcomes
- Non-functional requirements
- Durable correlation through stable business and technical identifiers
- Capacity and availability matched to the service-level objective
- Auditable state changes, configuration, and operator actions
Real-time fraud, sanctions, and payee controls
Returns a clear, reasoned outcome without letting a control timeout become an accidental approval.
- Kind
- control
- Owner
- Fraud and financial crime teams
- Responsibilities
- Assess transaction and party risk
- Apply payee-verification outcome where the service uses it
- Inputs
- Payment, customer, device, party, list, and behavioural data
- Outputs
- Clear, stop, challenge, or controlled timeout
- Controls
- Fail-safe policy
- List freshness
- Model/rule version
- Decision audit
- Failure modes
- Control timeout
- False positive
- Stale list or model
- Recovery
- Apply the documented fail-safe outcome
- Investigate without hiding the payment state
- Non-functional requirements
- Durable correlation through stable business and technical identifiers
- Capacity and availability matched to the service-level objective
- Auditable state changes, configuration, and operator actions
Instant clearing and routing service
Validates and routes the payment or settlement instruction continuously under the rail’s timeout rules.
- Kind
- external-network
- Owner
- Instant-payment infrastructure operator
- Responsibilities
- Confirm participant reachability
- Apply rail validation and duplicate controls
- Route or settle within the service clock
- Inputs
- Outputs
- Acceptance, rejection, timeout, or settlement outcome
- Controls
- Participant status
- Duplicate detection
- Service clock
- Availability
- Failure modes
- Unavailable receiver
- Network timeout
- Duplicate or invalid message
- Recovery
- Return the rule-defined outcome
- Support status enquiry and exception handling
- Non-functional requirements
- Durable correlation through stable business and technical identifiers
- Capacity and availability matched to the service-level objective
- Auditable state changes, configuration, and operator actions
Instant settlement accounts
Moves central-bank or designated settlement asset per transaction or under the rail’s funded model.
- Kind
- ledger
- Owner
- Central bank or instant-settlement operator
- Responsibilities
- Check funded capacity
- Post the settlement movement
- Return finality evidence
- Inputs
- Eligible instant settlement instruction
- Outputs
- Settlement debit and credit
- Controls
- Available funds
- Atomic posting
- Finality evidence
- Failure modes
- Insufficient prefunding
- Settlement service unavailable
- Posting uncertainty
- Recovery
- Reject or queue only where rules permit
- Reconcile the authoritative ledger before reopening
- Non-functional requirements
- Durable correlation through stable business and technical identifiers
- Capacity and availability matched to the service-level objective
- Auditable state changes, configuration, and operator actions
Receiving instant-payment engine
Validates the beneficiary and posts funds once the rail’s conditions and settlement evidence are satisfied.
- Kind
- application
- Owner
- Receiving payment product and technology
- Responsibilities
- Validate the destination account
- Respond within the rail clock
- Post once and report availability
- Inputs
- Instant payment
- Settlement outcome
- Outputs
- Beneficiary posting and response
- Controls
- Account status
- Duplicate posting protection
- Settlement-state check
- Failure modes
- Invalid account
- Receiver response timeout
- Core ledger unavailable
- Recovery
- Return the rule-defined response
- Repair posting idempotently after confirmed settlement
- Non-functional requirements
- Durable correlation through stable business and technical identifiers
- Capacity and availability matched to the service-level objective
- Auditable state changes, configuration, and operator actions
Status, exception, and reconciliation service
Connects customer status, network outcome, settlement, participant posting, return, and investigation evidence.
- Kind
- operations
- Owner
- Instant-payment operations
- Responsibilities
- Answer status enquiries from authoritative state
- Reconcile timeouts and late outcomes
- Control returns and investigations
- Inputs
- Network status
- Settlement evidence
- Participant postings
- Customer enquiry
- Outputs
- Truthful customer status
- Resolved timeout
- Return or investigation
- Controls
- Original-reference integrity
- Late-status ordering
- Four-eyes funds action
- Failure modes
- Late positive response after customer timeout
- Duplicate return
- Conflicting participant states
- Recovery
- Establish settlement first
- Correct customer status without duplicating value
- Use the rail's exception path
- Non-functional requirements
- Durable correlation through stable business and technical identifiers
- Capacity and availability matched to the service-level objective
- Auditable state changes, configuration, and operator actions
24×7 service operations and continuity
Maintains round-the-clock observability, capacity, failover, change, and incident ownership.
- Kind
- operations
- Owner
- Participant and infrastructure service operations
- Responsibilities
- Operate without a daily recovery window
- Coordinate participant and infrastructure incidents
- Protect the service clock during failover
- Inputs
- Latency, queue, error, liquidity, and dependency telemetry
- Outputs
- Incident action, capacity action, continuity decision
- Controls
- Error budget
- Change freeze and rollback
- Failover test
- On-call ownership
- Failure modes
- Cascading dependency latency
- Capacity exhaustion
- Uncoordinated maintenance
- Recovery
- Shed or stop safely under the rules
- Fail over without duplicate value
- Reconcile in-flight payments
- Non-functional requirements
- Durable correlation through stable business and technical identifiers
- Capacity and availability matched to the service-level objective
- Auditable state changes, configuration, and operator actions
Interfaces
Confirmed instant request
instant-payer → instant-sender
Start one idempotent payment and its end-to-end time budget.
- Contract
- api · synchronous
- Controls
- Authentication and authorisation
- Integrity and replay protection
- Correlation and audit evidence
- Failure treatment
- A channel timeout preserves the client reference for enquiry.
Bounded control request
instant-sender → instant-controls
Obtain explicit fraud, sanctions, and payee-control outcomes.
- Contract
- control · synchronous
- Controls
- Authentication and authorisation
- Integrity and replay protection
- Correlation and audit evidence
- Failure treatment
- Unavailable or late controls follow a documented fail-safe outcome.
Instant payment submission
instant-sender → instant-network
Submit the payment once participant checks and controls pass.
- Contract
- message · asynchronous
- Controls
- Authentication and authorisation
- Integrity and replay protection
- Correlation and audit evidence
- Failure treatment
- An ambiguous send is enquired before any retry.
Per-payment settlement
instant-network → instant-settlement
Move funded settlement asset under the rail's model.
- Contract
- settlement · synchronous
- Controls
- Authentication and authorisation
- Integrity and replay protection
- Correlation and audit evidence
- Failure treatment
- Insufficient funds or unavailable settlement returns the rule-defined outcome.
Routed payment and response
instant-network → instant-receiver
Deliver the payment and receive the beneficiary validation result.
- Contract
- message · asynchronous
- Controls
- Authentication and authorisation
- Integrity and replay protection
- Correlation and audit evidence
- Failure treatment
- A missing receiver response becomes a precise timeout state, not an automatic success.
Settlement evidence
instant-settlement → instant-receiver
Prove the settlement state used by the receiver's posting policy.
- Contract
- event · asynchronous
- Controls
- Authentication and authorisation
- Integrity and replay protection
- Correlation and audit evidence
- Failure treatment
- Delayed evidence is reconciled before duplicate or reversal action.
Beneficiary outcome
instant-receiver → instant-reporting
Record the receiving decision and posting state.
- Contract
- event · asynchronous
- Controls
- Authentication and authorisation
- Integrity and replay protection
- Correlation and audit evidence
- Failure treatment
- Late or conflicting outcomes enter ordered reconciliation.
Customer outcome
instant-reporting → instant-payer
Tell the payer only the outcome supported by current evidence.
- Contract
- api · synchronous
- Controls
- Authentication and authorisation
- Integrity and replay protection
- Correlation and audit evidence
- Failure treatment
- Unknown remains pending or timed out; it is not changed to failed merely to close the screen.
Service-clock telemetry
instant-network → instant-resilience
Expose availability, latency, error, and participant health.
- Contract
- operator · asynchronous
- Controls
- Authentication and authorisation
- Integrity and replay protection
- Correlation and audit evidence
- Failure treatment
- Telemetry loss raises an incident and does not fabricate payment status.