When Both Airlines Are Legacy

Executive Summary

• A Legacy x Legacy scenario is not where SRSIA creates the most immediate technical change, but it is where airlines can start standardizing language.
• The customer experience remains constrained by tickets, coupons, EMDs and schedule-driven interline rules.
• The practical work is to document ownership and data gaps now so the same partnership can migrate later.
• Legacy partners should avoid pretending that a renamed agreement has created order-native capability.

Why This Topic Matters

Most interline journeys still touch legacy processes. Ignoring Legacy x Legacy design creates a gap between strategic presentations and daily airport, call center and revenue accounting reality.

This scenario helps executives understand what SRSIA can and cannot change before the technology stack changes.

It also gives transformation teams a low-risk environment for defining future retailer-supplier terms without disrupting live operations.

Industry Background

IATA retailing work recognizes the move from legacy records toward Offers and Orders, but transition requires coexistence.

ONE Order aims to replace multiple record types with a single order reference, while legacy interline still relies on established records and settlement processes.

The gap between those two worlds is the reason retailer-supplier governance needs to start before every partner is technically modern.

The practical implication is simple: the customer promise has to be designed across offer, order, servicing, delivery and settlement, not only across shopping screens.

Detailed Explanation

Scenario: Both airlines remain ticket-native and use SRSIA as a preparation layer for future Offers and Orders.

In Legacy x Legacy interline, the basic lifecycle remains familiar. Availability is requested, fare construction follows filed fare and rule logic, the booking creates a PNR, payment leads to ticket issuance and ancillary services may require EMDs. Interline settlement follows agreed proration and billing procedures.

SRSIA does not magically convert that flow into an order. The value is conceptual and contractual. It asks the two airlines to describe who acts as retailer, who acts as supplier, what data needs to be preserved and what future capabilities should be supported when one or both parties modernize.

The common mistake is to use future-state labels while leaving operational teams with old ambiguity. If the call center cannot determine who owns a voluntary change, or finance cannot reconcile an ancillary, the partnership is not operationally ready no matter how modern the diagram looks.

A practical Legacy x Legacy SRSIA annex should list ticketing, servicing, disruption, baggage, ancillary and settlement responsibilities in current-state terms. That annex can then add target-state mappings to offer IDs, order IDs, order items and supplier events.

This scenario is also useful for data discovery. Which PNR remarks, SSRs, ticket coupons, EMD references and settlement fields are critical today? Those details become migration inputs for future order schemas.

Architecture and Operating Model Deep Dive

Offer and product governance

The offer layer is where the commercial promise is created, but it is also where many interline failures are introduced. In Legacy x Legacy, the offer should not be treated as a screen-level response. It needs supplier provenance, expiry, price guarantee, inventory constraint, product attribute, refundability and settlement intent. The key rule is that every product shown to the traveler must have a known fulfilment path and a known servicing path.

Filed fare and availability logic across legacy systems That owner should decide which supplier details are displayed directly, which are normalized into the retailer brand, and which are suppressed because the downstream lifecycle cannot support them. The product catalog, offer engine and partner adapter should work together so that the offer is not richer than the operational reality behind it.

Order and record strategy

PNR, ticket and EMD records This is the most important system-of-record decision in the scenario. Teams should not simply ask whether an order exists. They should ask which record is authoritative for passenger identity, itinerary, price, entitlement, fulfilment, supplier acknowledgement, payment, refund, exchange and settlement. In hybrid periods, more than one record may exist, but only one should be authoritative for each field.

A good order strategy keeps correlation visible. Offer ID, order ID, supplier order reference, PNR, ticket, EMD, payment reference, settlement reference and disruption event ID should be linked so customer service, airport, operations and finance teams can reconstruct the lifecycle without manual detective work.

Servicing and disruption design

Ticketing carrier for commercial servicing; operating carrier for airport and disruption execution This responsibility must be translated into concrete permissions: retrieve order, change itinerary, add item, remove item, refund item, split passenger, reprice supplier product, accept involuntary alternative and close an operational case. If a team cannot say which party may execute each action, the customer experience will depend on manual escalation.

Operating carrier operationally; validating carrier commercially The supplier owns operational facts such as cancellation, delay, aircraft swap, seat map change or airport delivery failure. The retailer owns the customer journey view. A modern disruption design converts the supplier event into recovery offers, customer choices, order updates, supplier confirmations and settlement adjustments.

Settlement and revenue accounting

Traditional proration, interline billing and dispute workflows Finance should be involved before launch because settlement fields are not back-office decoration. They determine whether a partner accepts the record, whether revenue can be recognized correctly, whether refunds are allocated to the right party and whether disputes can be resolved from evidence rather than email threads.

The finance-grade order item should carry product owner, seller, supplier, amount, taxes, commission, fulfilment status, refund status, change history and settlement reference. Where a legacy partner remains in the flow, the bridge must map those order item facts to ticket, coupon, EMD or billing records without losing commercial meaning.

Data, observability and audit

Every legacy airline interline SRSIA implementation needs an observability model. Teams should trace search request, supplier response, offer construction, customer selection, payment authorization, order creation, supplier confirmation, delivery event, servicing action and settlement event. The audit trail should show what each party knew at the time the customer promise was made.

Operational dashboards should be organized by partner, readiness state, platform, market and relationship type. A spike in order-PNR mismatches, supplier timeouts, failed order changes or settlement rejects should be visible before customers and finance teams discover the issue manually.

Partner onboarding and governance

SRSIA onboarding should be a product process, not only a legal process. Each partner needs a readiness score, supported lifecycle actions, API version inventory, test cases, exception handling model, disruption SLA, settlement evidence checklist and executive escalation path. The output should be a go-live decision that everyone can defend.

The governance model should also define change control. If a supplier adds a new ancillary, changes refund rules, migrates a market to order-native servicing or retires a legacy bridge, the retailer needs advance notice, regression tests and customer messaging updates.

Operational Scenario Walkthrough

1. Search trigger: The customer asks for a journey and the retailer identifies whether the flow is interline, codeshare or virtual interline. At this point the system should already know the readiness state of each partner and which fallback rules are allowed.
2. Supplier content request: The retailer requests supplier content with enough context for the supplier to return a meaningful promise. That context may include route, dates, passengers, loyalty status, channel, currency, point of sale, baggage needs and servicing requirements.
3. Offer assembly: The retailer assembles a customer-facing offer using supplier constraints. The offer should not hide material differences in product, baggage, seat, refund, change or disruption treatment. If a feature cannot be fulfilled or serviced, it should be excluded or marked as conditional.
4. Acceptance and payment: The customer accepts the offer. Payment, fraud, tax, commission and settlement allocations should be captured before the order is confirmed so the financial record can be reconciled later.
5. Order creation: The retailer creates the order or legacy equivalent. The supplier receives a fulfilment request or mirror record. Correlation IDs are written at this stage because retrofitting them after failure is expensive and unreliable.
6. Post-booking servicing: A change, refund or ancillary request is evaluated against both retailer policy and supplier capability. The customer sees a simple servicing action, while the back end may execute order change, ticket exchange, EMD update or supplier authorization.
7. Disruption event: The operating supplier sends an event. The retailer determines whole-journey impact, requests alternatives if necessary, displays customer options and records the accepted recovery path as an order update or legacy servicing action.
8. Settlement close: The retailer and supplier reconcile sale, change, delivery, refund and disruption evidence. Exceptions are routed to a dispute process with enough order and legacy references to avoid manual reconstruction.

SRSIA Annex Blueprint

A strong annex for Legacy x Legacy should begin with role definitions. Name the Retailer, Supplier, any selling intermediary, any platform provider and any operational delegate. Then define which role owns the customer relationship, which role owns the product promise and which role is allowed to make binding changes after purchase. This avoids the common situation where legal terms are clear but product teams still disagree on who may act.

The second annex area is product eligibility. List the routes, markets, passenger types, fare brands, ancillaries, bundles, loyalty benefits and service attributes that are allowed in the scenario. For each product, state whether it is searchable, sellable, changeable, refundable, disruptable and settleable. If an item is only supported in direct channels or only before ticketing, that limitation should be written into the operating model.

The third area is data exchange. The annex should specify mandatory fields for offer requests, supplier responses, order creation, supplier acknowledgement, servicing actions, disruption events and settlement evidence. It should also define timeout behavior, idempotency rules, duplicate message handling, version compatibility and minimum logging. These details are rarely glamorous, but they are what prevent operational disputes later.

The fourth area is customer treatment. Define what the traveler sees when a supplier product is unavailable, when a price changes, when confirmation is delayed, when a servicing action requires manual handling, or when disruption affects only part of the journey. The retailer should not have to invent customer language in the middle of an incident. The approved treatment should be part of the launch pack.

The fifth area is exception management. Every scenario needs named queues, SLAs, escalation paths and compensation authority. If a supplier cannot confirm, if order creation succeeds but settlement evidence fails, if a refund is accepted by one record and rejected by another, or if the customer is stranded between two partners, the annex should state who opens the case and who closes it.

The final area is change governance. SRSIA is not static. Airlines will migrate markets, retire bridges, add products, upgrade APIs and change servicing rules. The annex should require advance notice, regression testing, release notes, rollback procedures and joint operational readiness sign-off. This turns SRSIA from a launch document into a living operating contract.

Readiness Questions by Function

Implementation Roadmap

The roadmap should be repeated for each partner pair. One partner may be ready for shopping but not servicing. Another may support order events but still depend on legacy settlement. Treat readiness as a matrix by flow, not a binary partner label.

KPI and Control Framework

These metrics should be reviewed jointly by distribution, digital, operations, customer service and finance. SRSIA succeeds when ownership is visible across the lifecycle and failure modes are measured before they become structural cost.

Scenario Matrix

Comparison Table

Process Flow

1. Availability request
2. Fare and rule validation
3. PNR creation
4. Ticket and EMD issuance
5. Operating carrier fulfilment
6. Legacy settlement and dispute

Mermaid Diagrams

Process Flow Diagram

flowchart LR
  C[Customer] --> R[Validating or customer-facing airline]
  R --> SRSIA[SRSIA responsibility layer]
  SRSIA --> S[Participating operating airline]
  R --> O[PNR, ticket and EMD records]
  S --> D[Delivery and supplier events]
  D --> R

Sequence Diagram

sequenceDiagram
  participant Customer
  participant Retailer
  participant SRSIA
  participant Supplier
  participant Settlement
  Customer->>Retailer: Shop and choose itinerary
  Retailer->>Supplier: Request supplier content and constraints
  Supplier-->>Retailer: Return product promise
  Retailer->>Customer: Present combined offer
  Customer->>Retailer: Accept and pay
  Retailer->>SRSIA: Create accountable order context
  SRSIA->>Supplier: Confirm fulfilment obligation
  Supplier-->>Retailer: Send delivery or disruption events
  Retailer->>Settlement: Generate settlement evidence

Swimlane Diagram

flowchart TB
  subgraph Customer
    c1[Search] --> c2[Accept offer] --> c3[Receive updates]
  end
  subgraph Retailer
    r1[Compose offer] --> r2[Create order] --> r3[Service customer]
  end
  subgraph Supplier
    s1[Return availability] --> s2[Confirm fulfilment] --> s3[Send operational event]
  end
  subgraph Finance
    f1[Capture price owner] --> f2[Allocate settlement] --> f3[Reconcile dispute]
  end
  c1 --> r1
  r1 --> s1
  c2 --> r2
  r2 --> s2
  s3 --> r3
  r3 --> f2

Risks, Benefits and Controls

Key Takeaways

• Legacy x Legacy is a baseline, not the target.
• SRSIA language can be introduced before technical migration.
• Document current ownership in enough detail to support future order mapping.
• Do not promise order-native servicing until the actual systems support it.

FAQ

SEO Metadata

Suggested Social Media Snippets

• When Both Airlines Are Legacy: a practical SRSIA scenario for airline retailing teams. https://www.modernairlineretailing.com/blog/2026-06-10-when-both-airlines-are-legacy.html
• If your interline roadmap stops at shopping, you are missing servicing, disruption and settlement. Read: When Both Airlines Are Legacy.
• Retailer-Supplier design question: who owns the customer promise when platforms and readiness differ? Legacy x Legacy

Interactive Graphic Specification

• Default state in the SRSIA Scenario Explorer should highlight Legacy x Legacy.
• Controls: airline A state, airline B state, platform, relationship and transition maturity.
• Outputs: owner table, complexity heat map, Sankey flow, swimlane, sequence diagram, architecture diagram and readiness matrix.
• Primary KPI: time for a product manager or architect to answer who owns offer, order, servicing, disruption and settlement.

Image Prompts for AI Generation

• A clean executive aviation technology infographic showing When Both Airlines Are Legacy, with two airline system blocks, an SRSIA layer, order items and settlement lines, realistic airport operations background, modern editorial style, no logos.
• A detailed airline retailing architecture diagram for Legacy x Legacy, showing retailer, supplier, offer, order, disruption event and settlement evidence, high contrast, professional consulting visual.
• A product manager dashboard visualization for legacy airline interline SRSIA, with readiness matrix, heat map and interline lifecycle timeline, modern airline technology aesthetic.

Internal Links and Related Articles

• SRSIA Scenario Explorer
• SRSIA & Interline Retailing Knowledge Hub
• Interline Offer & Order Architecture
• The Complete SRSIA Scenario Matrix
• Retail Ready Airline vs Legacy Airline

References

Only publicly available sources from the approved source set are used. The analysis above is independent and implementation details vary by airline, vendor and partner agreement.

• IATA Airline Retailing
• IATA Fulfilment with Orders (ONE Order)
• IATA Interlining with Offers and Orders
• IATA Settlement with Orders
• ATPCO order servicing and settlement