Definition and responsibility
A debit card spends against a linked deposit account’s available funds. This module owns that linkage and card-specific account controls; the network message engine and the deposit ledger own their separate records.How it differs from related modules
Read the module comparison map for the whole platform and the glossary for shared terms.
Planned operating duties: Cardholder; debit-card operations; fraud reviewer. Access to these duties requires the approved institution permission matrix. The bank or authorised regulated entity owns product policy and financial outcomes. Platform operators receive no automatic customer-data, fund-movement or issuer authority.
Worked Indian example
Use the four stages below to distinguish the initial facts, the action to test, confirmed completion and the alternate result. This example exercises this module’s responsibility; related modules still own the handoffs listed above. Fictional requirements illustration, not seeded data or approved banking policy. Reference: CARD-001 / INR 1,000.00 purchase.
No real customer, regulator approval, provider connection or bank operation is asserted. Illustrative amounts have currency INR and scale 2; actual economics/authority must be supplied by the institution.
Module flow diagrams
Read each flow from top to bottom. Rectangles are actions or recorded outcomes; diamonds are decisions; labelled arrows show the next permitted route. The denial route stops the operation. The pending/unknown route keeps the original reference for investigation instead of claiming success. Each diagram corresponds to the numbered journey below. Planned workflows are shown below. Execution depends on confirmed institution policy and interface contracts.Flow 1: Link eligible account to release remaining hold
Flow 2: Merchant reverses purchase to reconcile customer funds
Required features
Planned functionality is listed below. Implementation requires confirmed field definitions, permissions, state transitions and product economics for the selected offering.Required configuration
Eligible funding accounts; primary/add-on mandate; channels; domestic/international; limits; fees; PIN lifecycle. Store approved values in versioned, effective-dated product/programme policy. Capture the exact configuration version used by an instruction. Missing mandatory configuration blocks the dependent action; enabling a menu cannot grant legal authority.End-to-end journey 1
Link eligible account → activate card/channel → authenticate transaction → reserve funds → receive presentment → post once → release remaining hold. The journey ends only when its authoritative result, customer/staff-visible result and related book or case history agree. A saved request, queue entry or HTTP acknowledgement is an intermediate state.End-to-end journey 2
Merchant reverses purchase → match original authorisation → release or reverse under finality rules → reconcile customer funds. Every transition needs an authorised actor, original version and recorded reason where required. Cancellation or client disconnection does not prove server rollback. Financial corrections retain their original reference and use linked reversal/adjustment entries rather than deleting history.Interfaces and data dependencies
Deposit balance/holds; issuer authorisation; clearing; secure PIN; network settlement. Agree stable institution, product, party and operation references; source version; as-of time; completeness; status/finality; retry rules and correction handling. Where no financial posting occurs, record the administrative/case outcome instead of inventing a journal. All channel requests use server-verified identity and institution scope. Partner, branch and customer access is narrower than institution membership. Lists, details, search, exports, callbacks and files must enforce the same boundary.Current implementation and reuse
New Banking project: proposed, not built. No debit card processing exists. Reviewed legacy feature boundaries: No operational source module was found. Legacy feature presence is a reuse candidate, not acceptance or deployment evidence for this module.Acceptance criteria and exception scenarios
Explicit cases: Frozen account; insufficient funds under parallel spends; presentment after block; refund after replacement.- Allowed success: confirm saved/output values, authoritative status and the exact approved actor/channel.
- Denial: reject foreign institution, unauthorised branch/customer/programme and revoked or expired access without information leakage.
- Reliability: prove stale-version rejection and concurrency behaviour; retryable commands apply one economic effect; unknown financial outcomes are reconciled by original reference.
- Records and usability: preserve redacted audit, monetary precision and document integrity; verify keyboard/mobile, direct links, expired sessions, Back/Forward and return navigation. Internal web navigation preserves its workspace.