Interline billing and settlement where every rejection is answered inside its time limit, coupon by coupon
Every rejection answered inside its time limit, with every coupon tied to its agreement.
See one case, screen by screen ↓Interline billing and settlement is how airlines bill each other for the coupons they fly on each other's tickets, through IATA Simplified Invoicing and Settlement (SIS), and settle through the IATA Clearing House or the Airlines Clearing House. Interline Billing and Settlement builds and checks each period's prime billing, reads every rejection memo coupon by coupon, drafts the cited answer and reconciles each settlement advice with seven agents, and a person approves every answer before it goes.
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Interline billing and settlement runs on a monthly rhythm: the airline that flew a coupon bills the airline that issued the ticket through IATA SIS, prorated under a special prorate agreement or the MPA straight rate, and the money moves through the IATA Clearing House or the Airlines Clearing House. Partners reject part of every period's prime billing, and each rejection memo starts a ladder — stage 1, the re-rejection at stage 2, rejection again at stage 3, then correspondence — every rung with its own time limit.
Today an interline analyst reads each memo coupon by coupon, matches it to the ticket and the flown record, looks up the agreement, and decides by habit whether to fight. The answer is written by hand, the evidence attached by hand, and the time limit kept in a spreadsheet. When a limit passes, the money is gone. When an agreement is coded wrong — on one side or both — the same coupons come back rejected next month, and the month after.
Estimated hours for one stage-1 prorate rejection of 118 coupons, answered by an analyst by hand and with the agents.
Seven agents build and check the billing, read every rejection, decide accept or fight per coupon and draft the cited answer; a person approves each one.
On Oct 1 Corvane Airways billed Norvia Airlines for September P4: 1,246 coupons, $447,860.40. On Oct 9 Norvia rejected 118 of them, $42,310.00, for prorate value. Here is what happens next in the working solution, on Thursday, October 15, 2026.
Lauren's day opens on what needs her: 18 disputes worth $196,749.40, three due within 7 days; October P3 billing with 43 of 46 invoices ready and 3 held; and October P2 settlement, $4,812,170 on Fri, Oct 23, $14,140.00 short and already traced. Overnight the agents read 14 rejection memos, matched 2,113 coupons to tickets and flights, drafted 9 answers and built and checked 46 invoices.
Accept-or-fight analyst: “Norvia rejected $42,310.00 on 118 coupons for prorate value. 109 are right under SPA Amendment 3; 9 were issued before it took effect, so I propose to accept those.”
Rung one is Corvane's billing; rung two, set in like the other side of a conversation, is Norvia's stage-1 rejection, memo NOR-RM1-2610-0731: “Prorated per MPA straight rate; SPA values not applicable.” Beside it, the rejection reader says it matched every coupon to its ticket and to Corvane's flown record, and that Norvia valued them at the MPA straight rate. The coupons are premium-cabin connections to and from ORD on Norvia tickets.
Every statement carries a numbered citation that opens the memo, the clause or the flown record.
109 tickets were issued on or after Sep 1, so SPA Amendment 3 applies and its fixed prorates stand: re-reject $39,170.00, 97% confident. 9 tickets were issued Aug 24–31, when Amendment 2 still left premium cabins to the MPA: accept $3,140.00, and Norvia keeps the credit. Each coupon opens with its issue date, flown date, Corvane's billed value, Norvia's value and how the agents decided.
On each coupon: “Checker agrees. Read from the ticket and the agreement, never from the draft.”
A separate checker recomputes all 118 coupons from the SPA text and the issue dates alone, never from the analyst's working, and agrees on every coupon. The rebuttal drafter then writes the stage-2 memo that goes to SIS, citing Amendment 3 §1.2 and §4.2 and attaching the 109 flown records. Corvane's target is to answer by Oct 30.
Lauren types her question beside the ladder. The answer comes with its sources: the 9 tickets were issued between Aug 24 and Aug 31, Amendment 3 applies only to tickets issued from Sep 1, and Amendment 2 leaves premium cabins to the MPA — so Norvia's values stand on those 9. The analyst also names the cause: Corvane's own coding used the flown date, and Norvia's system does not hold Amendment 3 — 412 coupons rejected since Sep 1.
“Our own coding used the flown date instead.”
Approve and send opens the decision: re-reject 109 coupons, $39,170.00, and accept 9, $3,140.00, in October P3 with the evidence attached. She picks reason code A1 · The agreement supports our value, can add a note for the audit trail, and ticks the statement before she signs as Interline Billing Manager.
“I have read the agents' evidence and approve this answer for Corvane Airways.”
The stage-2 memo, CRV-RM2-2610-0212, is acknowledged by SIS and the ladder records who approved it and why. Below it, a dashed rung shows Norvia's move at stage 3 and its limit. The analyst offers the two follow-ups: a letter to Norvia and a fix to Corvane's own coding, both for a person to approve.
“If Norvia rejects again, the agents read it the day it arrives and bring you the next rung. The time-limit keeper watches the date.”
October P3 closes Wed, Oct 21 at 5:00 pm CT. The pre-submission checker runs 9 checks on every invoice, including every cause found in this month's rejections, and has held 6 coupons on Norvia's invoice CRV-2610P3-NOR: tickets issued Aug 28–31 that would be billed at Amendment 3 values. Re-valuing them under the MPA changes the invoice by −$2,090.40, to $460,027.80, if a person approves the correction.
“Billing them at Amendment 3 would bring another rejection.”
The rebuttal drafter writes to Henrik Aaltonen, Norvia's head of interline accounting: since Sep 1 Norvia has rejected 412 premium-cabin coupons, $148,960.00, in four memos, because Amendment 3, signed Aug 14, 2026, is not yet loaded in Norvia's system. The letter owns Corvane's error on the 9 coupons and asks for a call. It waits for Grant's approval, with every number cited.
“Loading Amendment 3 would close the open memos and prevent new ones.”
The settlement reconciler matched the October P2 clearing house advice, $4,812,170.00, against an expected net of $4,826,310.00 and traced the $14,140.00 difference to Talvera's protest of 6 coupons it says were billed twice — they were billed once, and the answer is drafted. Elena confirms the advice with the difference explained. Of three write-offs proposed, Veloria's $31,480.00 lapsed in correspondence on Aug 31, before the agents; above $25,000 it needs Diane, the Controller, to co-sign.
“$14,140.00 short: Talvera protested 6 coupons as billed twice.”
The same rejection, seen by the five people who carry it — what their month looked like, and what it looks like now.
Seven agents build and check the billing, read every rejection, decide accept or fight per coupon and draft the cited answer; a person approves each one.
Handles interline invoicing for each period, building the prime billing from flown coupons: one invoice per partner per clearance period, prorated by the SPA or the MPA in force on the ticket's issue date, with the interline service charge, taxes and the IATA rate.
Runs 9 checks on every invoice before it goes — billing value, prorate and agreement, agreement in force, ISC, taxes, duplicates, exchange rate, supporting documents, and every cause found in this month's rejections. On disputes it is the independent checker that recomputes each value from the agreement and issue dates alone.
Reads every rejection memo, protest and letter from IATA SIS and matches each coupon to its ticket, flight and billing, saying what the partner claims in plain words with the passage.
Decides per coupon whether Corvane or the partner is right, with a confidence and the cost to fight, and finds patterns across memos and partners — such as one partner's system missing an amendment.
Drafts stage-2 and stage-3 answers, correspondence and partner letters in plain, courteous language, citing the clause, the ticket and the flown record.
Puts the time limit on every stage and letter from the limits set in Settings, raises what is due within 5 business days, and has the next step drafted before a limit passes.
Reconciles interline settlement: checks every IATA Clearing House and Airlines Clearing House advice against what Corvane billed and was billed, to the cent, and traces each difference to its invoice or protest.
The manager approves every answer, acceptance and hold; the Controller co-signs write-offs above $25,000. The agents propose; a named person decides.
Beside every dispute, settlement and report, ask in plain words or tell the agents what to change. Answers cite the agreement, the memo or the record behind them.
Why accept 9?
The 9 tickets were issued between Aug 24 and Aug 31. Amendment 3 applies only to tickets issued from Sep 1, and Amendment 2 leaves premium cabins to the MPA. So Norvia's values stand on those 9: $3,140.00. Our own coding used the flown date instead.
What happens if Norvia rejects again?
Corvane answers stage 1 within 21 days, so by Oct 30. If Norvia rejects again, that is stage 3, and the time-limit keeper puts their date on the ladder. After stage 3, the dispute moves to correspondence, where each reply has its own limit.
Why is October P2 settlement $14,140 short?
Talvera protested 6 coupons as billed twice; the billing history shows they were billed once. The answer is drafted. I have opened the settlement.
Why can't we fight Veloria?
The correspondence limit passed on Aug 31 with no reply from Corvane. After that Veloria need not answer, so there is no route to the money. Writing it off needs your approval and the Controller's.
13 screens from the working solution, on its sample data. Pick one to see it large.
Your own targets and thresholds are settings the interline billing manager approves; the IATA RAM time limits come from the Revenue Accounting Manual edition in force, loaded each year by the systems administrator. Every change is on the audit trail.
| Setting | Default | Choose from |
|---|---|---|
| Corvane answers a stage-1 rejection within | 21 days of receipt | Any number of days |
| Raise correspondence replies before the limit by | 5 business days | Any number of business days |
| Passenger prime billing time limit | 3 months | Taken from the Revenue Accounting Manual edition in force |
| Each rejection stage (2 and 3) time limit | 4 months | Taken from the Revenue Accounting Manual edition in force |
| Bulk approval, largest value per proposal | $10,000 | Any dollar amount |
| Bulk approval, lowest agent confidence | 95% | Any percentage |
| Do not fight past stage 3 below | $1,000 | Any dollar amount |
| Controller co-signs write-offs above | $25,000 | Any dollar amount |
Every figure is labelled: a target the solution is built to, an estimate, a typical published result, or a proven one.
“demo” = seen in the working solution, on its sample data · “target” = the design goal, measured in the live solution · “estimated” = our estimate · “typical” = published figures (IATA SIS — 1.94 million invoices worth USD 89 billion a year among nearly 500 airlines; IATA Passenger Rejection Reduction Best Practices v1.2, 2021 — the 32% target, and an example airline report with stage-1 rejections at 4.39% of prime billings and 59% of stage-2 answers rejected again). Corvane Airways, its partners and the people named on this page are fictional — characters and sample data in the working solution.
Interline billing and settlement is how airlines bill each other for the coupons they fly on each other's tickets, through IATA Simplified Invoicing and Settlement (SIS), and settle through the IATA Clearing House or the Airlines Clearing House. Interline Billing and Settlement builds and checks each period's prime billing, reads every rejection memo coupon by coupon, drafts the cited answer and reconciles each settlement advice with seven agents, and a person approves every answer before it goes.
The rejection reader matches every coupon in the memo to its ticket and flown record. The accept-or-fight analyst proposes, per coupon, whether to re-reject or accept, with a confidence; an independent checker recomputes each value from the agreement alone; and the rebuttal drafter writes the stage-2 or stage-3 memo citing the clause with the evidence attached. A person approves it with a reason code, and it goes to IATA SIS.
Rejection memo reduction starts before the billing goes: the pre-submission checker runs 9 checks on every invoice, including every cause found in this month's rejections, and holds failing coupons for a person. When a partner keeps rejecting for one cause — such as an SPA amendment missing from its system — the agents find the pattern and draft a cited letter. Corvane's target is 32% fewer rejections than today, 2.1% by October 2027: the same cut IATA's members once aimed for over five years.
For ICH settlement, and for the Airlines Clearing House, the settlement reconciler checks each advice against what was billed and billed to you, to the cent, and traces any difference to its invoice or protest. In the demo it traced a $14,140.00 shortfall to a partner's protest of 6 coupons and linked the drafted answer. The settlement accountant confirms the advice.
Each stage and letter carries the time limit from the Revenue Accounting Manual edition in force — in the working solution, 3 months for passenger prime billing and 4 months for each rejection stage — which the systems administrator loads each year and the interline billing manager approves. The time-limit keeper raises correspondence 5 business days before its limit, with the reply already drafted.
No. The agents read, match, check, draft and propose; they never send, accept, submit, confirm or write off. Every decision is signed by a person with a reason code, within the limit of their role, and write-offs above $25,000 need the Controller's co-signature. Every step is on the audit trail.
Yes. The billing builder prorates each coupon under the SPA in force on the ticket's issue date, otherwise the MPA, and the agents read agreements and amendments clause by clause. In the demo, the 9 coupons issued before SPA Amendment 3 took effect were accepted under the MPA, and the 109 after it were re-rejected.
The Agentic Solution Engine builds and deploys it from your requirements and documents — your agreements, interline procedures, time limits and a sample of past billing, rejection memos and settlement advices — and it goes live once every quality gate has passed. First-time set-up connects IATA SIS, the clearing houses, revenue accounting and lift, then loads partners and agreements and assigns roles.
Yesterday's flights earned by morning, and the revenue lost in suspense back on the books.
1-min demoSpecial Prorate Agreement ManagementEvery agreement tested on real trips before it bills; no partner billed on a lapsed one.
1-min demoAirline Sales AuditEvery ticket audited, not a sample, and every memo sent with its proof.
1-min demoWe'll run Interline Billing and Settlement on a sample of your own past billing, rejection memos and settlement advices.