WorkflowFinance & Revenue Accounting

Airport Charges Audit

An airport charges audit that ticks every billed landing against what flew, and follows every overcharge to the credit

Every billed landing checked against what flew, and every overcharge credited.

See one case, screen by screen ↓
demo214,906linesticked overnight across 145 airport and navigation bills in the working solution
demo$27,640.48overbilled on one LAX bill — a wrong weight and three diverted flights — agreed to the cent by a second agent
target100%of invoice lines checked against flights, weights and tariffs, not a sample
target90%of disputed value credited within 90 days, tracked to cash
In short

What is Airport Charges Audit?

Airport Charges Audit is an airport charges audit run by AI agents: it checks every airport and air navigation charge against the flights the airline flew, the certificated weight of the tail that flew and the tariff in force that day. It replaces the sampled airport charges reconciliation done in spreadsheets with airport invoice validation of every line: eight agents read each bill in any format, tick every line, re-derive each finding independently and draft the dispute; the airport cost analyst approves and signs, and the credit is tracked to cash.

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Updated

The problem

Why airport bills get paid as billed

Airport and air navigation charges are one of an airline's largest costs, and without an airport charges audit they are paid as billed. Every airport and every navigation provider bills them monthly in its own format: IATA SIS supplier invoices, PDFs by email, portal files and scanned paper. Accounts payable keys the header total; the line detail is rarely keyed at all. An airport cost analyst exports the flown schedule and the fleet register and checks a sample of landings in a spreadsheet, then looks up the airport's rates and charges for the fiscal year and the terms of the airline use agreement.

The money sits in the lines nobody had time to check. At US airports, landing fees are billed per 1,000 lb of maximum gross landed weight, so one wrong weight in a register is billed on every landing. Diverted and canceled flights stay on the bill because the airport billed from the schedule, tariffs change mid-year, a parking free window is ignored, and air navigation route charges are billed on the filed route instead of the route flown, or on another type's MTOW. When a dispute does go out by email, someone has to remember to check that the credit memo arrives and is applied — and credits go stale.

typical15–16%of an airline's costs are airport and air navigation charges
typical3.6%error rate when invoice data is re-keyed by hand
typical393landingsfound reported at the wrong weight in one airport audit of one carrier
Where the hours on one large airport bill goestimated
By hand30 days
With the solution1.8 days
  • Reading and keying the invoice lines6 → 0.1 d
  • Matching billed landings to flight records10 → 0.5 d
  • Checking weights and the tariff in force6 → 0.3 d
  • Writing the dispute and gathering evidence4 → 0.5 d
  • Short-pay instruction to accounts payable1 → 0.1 d
  • Chasing and matching the credit memo3 → 0.3 d

Estimated split, in hours, for checking one large monthly airport bill line by line — by hand, where it is done at all, and with the solution, where the person reviews the agents' findings and signs.

How it works

How a bill moves

Eight agents tick every line, check each other and draft the dispute; the cost analyst signs.

What comes in
Bills in145 bills a month · e-invoices, PDFs, portal files, scans
Agents at work
Invoice readerany format
Then
Movement matcherflight records
Weight and tariff checker
Navigation charge checker
Then
Verifierre-derives on its own
Then
Dispute drafter
Credit tracker
Cost trend watcher
A person decides
Airport Cost Analystapproves, edits or rejects, and signs
What comes out
Cited dispute
Short-pay to AP
Credit tracked to cash
One case, step by step

An airport charges audit, screen by screen: one LAX bill to a signed dispute

Corvane Airways, a fictional network carrier hubbed at DEN, receives LAX's September invoice LX-26-09-0412 on Oct 2 as an IATA SIS e-invoice: $1,240,318.40 on 1,567 lines, due Nov 1, dispute window to Dec 1. This is how the airport charges audit runs, screen by screen, in the working solution.

  1. 01Thursday, 10:24 am MT

    What the agents did overnight, and what needs her

    Dana Whitaker · Airport Cost Analyst

    September bills are in. Overnight the agents read 145 invoices and ticked 214,906 lines against Corvane's flights, weights and tariffs. Her home screen shows 145 of 162 expected bills received, $501,296 of overbilling across 17 bills that need her, and $1,064,212 of credits outstanding on 38 disputes. LAX is at the top.

    Movement matcher: “Nine movements do not match: 6 landings of a 787-9 at 777-300ER weight and 3 flights that diverted on Sep 21 and never landed. $27,640.48; the dispute letter is drafted.”

  2. 02The tally

    The whole bill as one tape: 1,555 lines tick

    The agents

    LAX's bill is a tally tape, one tick per billed line, grouped by charge and by day. Landings: 1,142 lines at $6.17 per 1,000 lb, $920,823.25; the international arrivals facility: 60 lines, $246,927.00. Matched ticks are quiet. Eleven lines the agents resolved on their own carry their reason — 4 tail swaps of the same type, 3 ferry landings, 2 flight-number changes and 2 arrivals after midnight UTC. Twelve lines do not match, and each one says why.

    “Hover a tick to read it; click to see the records.”

  3. 03Run the check again

    Every agent's step, in view

    The agents

    Dana re-runs the check to see it step by step. The Invoice reader reads 1,567 lines from the e-invoice, totals agreeing to the cent. The Movement matcher matches 1,142 landings to flight records and finds 3 with no LAX arrival. The Weight and tariff checker re-prices on the FY2026–27 tariff and the weights register. The Verifier re-derives every finding independently and agrees; the Dispute drafter writes the letter and the short-pay instruction; the hand-off waits for Dana.

    “Same result as this morning. Nothing changed on the bill or in the records.”

  4. 04Finding 1

    A 787-9 billed at 777-300ER weight

    Weight and tariff checker · Verifier

    Six landings of N831CV on CV 118 from NRT — Sep 9, 12, 16, 19, 23 and 27 — were billed at 554,000 lb. N831CV is a 787-9 certificated at 425,000 lb. At $6.17 per 1,000 lb that is $795.93 too much on each landing: 6 × (554 − 425) × $6.17 = $4,775.58. The Verifier re-derived it from the records on its own, to the cent.

    Every value carries a numbered citation that opens the invoice line, the weight certificate or the tariff passage.

  5. 05Finding 2

    Three diverted flights — and why the ferries stay paid

    Dana Whitaker · Airport Cost Analyst

    On Sep 21 runway 25L closed in fog. CV 62 diverted to SFO, CV 940 to LAS and CV 176 to ONT, yet LAX billed their landings and the arrivals facility for 812 passengers: $22,864.90. ACARS shows each “in” at the diversion airport, and LAX's own movement data has no arrival. Dana asks why the ferry landings are not disputed too; the agents answer with the flight records.

    “The ferry landings on Sep 22 were real landings at LAX… The agreement bills each revenue and non-revenue landing, so we pay them. We dispute only the Sep 21 arrivals that never happened.”

  6. 06Root cause

    The wrong weight was Corvane's own

    Cost trend watcher

    The agents look for Corvane's own errors first. On Sep 8, when four tails moved over from Halvard Air, row 212 of Corvane's fleet file gave N831CV the row of N731CV, a 777-300ER. The airport billed what Corvane sent, the file went to 41 airports, and SFO billed 2 landings the same way. The corrected row is ready, and goes to the 41 airports only when a person approves it.

    The Cost trend watcher proposes fixes; it never changes a register or a tariff.

  7. 07Signed and sent

    She signs the dispute; accounts payable short-pays

    Dana Whitaker · Airport Cost Analyst

    The Dispute drafter's letter to LAX Revenue Accounting cites §7.4 of the airline operating agreement, sets out each item with its evidence and owns Corvane's fleet-file error. Dana signs with the reason code “Billing error — weight and movements”. Accounts payable is told to pay $1,212,677.92 by Nov 1 and hold $27,640.48 against dispute AC-D-2610-001, and the Credit tracker starts watching the reply clock.

    “I have reviewed the findings and the evidence, and I approve this dispute on behalf of Corvane Airways.”

  8. 08Above $50,000

    The hub's gate charge goes for co-signature

    Robert Hale · Airport Affairs Director

    DEN billed $412,800.00 for gates B21–B36 that Corvane's Concourse B lease already covers — section 5.2 includes the use of those gates in the rent. The Verifier agrees and the dispute is inside its window, but it is above Dana's $50,000 limit, so she approves it and sends it to Robert Hale to co-sign before anything goes to the airport.

    “Limit — Above $50,000: Robert Hale co-signs.”

  9. 09When the agents disagree

    Two workings, and a person chooses

    Verifier

    On FRA's bill the Weight and tariff checker read the engine emissions data as class 2 for 8 landings, $4,118.40 overbilled. The Verifier read the same table as class 3 for the engine variant on 2 of the tails, which would cut the finding to $1,029.60. Nothing goes out on one agent's word: both workings are kept and Dana chooses.

    “The Verifier disagrees. Both workings are kept; a person chooses.”

  10. 10Weeks later

    Every dispute followed to the cash

    Credit tracker

    The LAX dispute joins the credits list, reply due Nov 29. JFK is 17 days past its reply clock on an $18,240.60 dispute, so a chaser is drafted for approval. ORD's credit memo CM-26-0418 for $9,420.00 on the September invoice matches its July dispute and waits for Dana to confirm. Recovered this year: $3,842,610.

    The Credit tracker never writes off a dispute; a write-off needs a person.

Who it’s for

Built for everyone who answers for the airport bill.

The same bill, seen by the five people who carry it at Corvane — what their month looked like, and what it looks like now.

DW
Dana WhitakerAirport Cost Analyst, Finance — Denver · signs disputes to $50,000
Airport Cost Analyst
Before
Checks a sample of landings in a spreadsheet and writes disputes by email. “Don't show me 1,567 lines. Show me the nine that are wrong and prove the rest.”
Now
Opens a bill already ticked line by line, reads the nine notes, asks the agents about any line and signs the drafted dispute.
MR
Marcus ReyesStation Finance Manager, West — LAX, SFO, SEA, HNL
Station Finance Manager, West
Before
Gets station questions by email weeks after the bill. “If LAX says we landed, I want the ACARS record in one click.”
Now
Answers the questions routed to his stations — like confirming N310CV left HNL on Sep 12 at 6:05 am — and his answer is on the record.
JK
Janet KowalskiAccounts Payable Lead · releases, short-pays and applies credits
Accounts Payable Lead
Before
Pays airport bills on the due date with no line detail. “Tell me what to pay and what to hold, before the due date.”
Now
Gets an instruction per dispute — pay $1,212,677.92 by Nov 1, hold $27,640.48 — and releases clean bills in bulk.
RH
Robert HaleAirport Affairs Director · co-signs disputes above $50,000
Airport Affairs Director
Before
Owns the use agreements and hears about large disputes late. “A gate dispute at our own hub is a relationship conversation, not an email.”
Now
Sees every dispute above $50,000 with the lease clause and the evidence before it leaves, and adds the second signature.
SI
Sam ItoFinance Systems Administrator · channels, roles and rules
Finance Systems Administrator
Before
Maintains exports and lookups that only one analyst understands. “Every rule change should be signed and visible, like an invoice.”
Now
Sets thresholds and rules once; each change is tested on last month's bills before it takes effect and is on the audit trail.
Built on the engine

8 agents. Each with one job, and hard limits.

Eight agents tick every line, check each other and draft the dispute; the cost analyst signs.

Invoice reader

Reads every airport and navigation bill in any format — IATA SIS e-invoices, PDFs from the inbox, airport portal files and scans — into lines, with a confidence for every field, and asks a person when it is not sure.

  • Never edits an invoice
  • Fields read under 92% confidence go to a person; totals must agree to the cent before any line is checked
Movement matcher

Ticks each billed movement against Corvane's flight records (OOOI and ACARS times) and the airport's movement data, resolving tail swaps, ferry flights, flight-number changes and UTC dates, and finding diversions and cancellations.

  • Decides a movement did not happen only when two independent sources agree
  • Explains every exception it resolves
Weight and tariff checker

Re-prices every line from the certificated weight of the tail that flew and the tariff in force on the movement date — landing fees per 1,000 lb of maximum landing weight, passenger charges, gates, parking and ground power.

  • Uses only certificated weights from the weights register
  • Uses only published or agreed rates
Navigation charge checker

Recomputes air navigation route charges from the route Corvane actually flew: distance, weight factor from the takeoff weight, and each provider's unit rate.

  • Only flights Corvane operated
  • Never estimates a missing track
Verifier

Re-derives every finding from the records without seeing the first agent's working. When it disagrees, both workings go to a person.

  • Cannot create findings — it only agrees or disagrees
  • Independent of the checkers
Dispute drafter

Drafts the dispute letter citing the agreement clause and each line's evidence, the short-pay instruction to accounts payable and the evidence pack.

  • Never sends — a person approves and signs
  • Plain, courteous, one item per finding; owns Corvane's own errors
Credit tracker

Follows each dispute to cash: the airport's reply clock, chasers drafted before it lapses, and credit memos matched by dispute number, amount and period when they land on a later bill.

  • Never writes off
  • Never chases without a person's approval
Cost trend watcher

Explains each station's change in cost — volume, aircraft mix, tariff and billing error — reads new rate letters, and traces root causes, including Corvane's own.

  • Proposes fixes; never changes a register or a tariff
  • A new rate is used only after a person confirms it
Cost analyst

Signs every dispute; the Airport Affairs Director co-signs above $50,000. The agents propose; a named person decides.

Ask in plain words

Ask the agents about any line

Every working screen has an ask box. Ask about a line, a rate or a date — or tell the agents what to do. Answers cite the invoice line, the flight record, the weight certificate or the tariff passage.

Why not dispute the ferry landings?

The ferry landings on Sep 22 were real landings at LAX: CV 9062 from SFO, CV 9940 from LAS and CV 9176 from ONT, with no passengers. The agreement bills each revenue and non-revenue landing, so we pay them. We dispute only the Sep 21 arrivals that never happened.

Why is N831CV billed at 777 weight?

N831CV is a 787-9 certificated at 425,000 lb, but six landings were billed at 554,000 lb. The cause is ours: our Sep 8 fleet file gave N831CV the row of a 777-300ER. I have a corrected file ready for the 41 airports that received it.

What should AP pay?

Pay $1,212,677.92 by Nov 1 and hold $27,640.48 against the dispute. The agreement lets us dispute within 60 days and pay the rest when due.

Hold all Sep 21 lines

Done. I have held the 6 lines dated Sep 21 for CV 62, CV 940 and CV 176 from payment, $22,864.90, and told Accounts Payable. Every other Sep 21 line ticks and stays payable.

Every screen

The working solution, as it ships.

13 screens from the working solution, on its sample data. Pick one to see it large.

TodayThe airport charges audit home: bills received, overbilling that needs the analyst, credits outstanding, and what the agents found overnight.
Landing fee audit, line by lineLAX's bill ticked line by line against flights, certificated weights and the tariff, with the agents' findings, citations and the ask box beside it.
The check, step by stepEach agent's step on the LAX bill: read, matched to flights, re-priced on weights and tariff, verified, letter drafted, handed to the analyst.
A conversation on the lineThe analyst asks why the ferry landings are not disputed; the agents answer from the flight records and the agreement.
Aircraft weights and the root causeThe weights register and Corvane's own fleet-file error that sent a 787-9 as a 777-300ER, with the corrected row waiting for approval.
The airport invoice dispute, signedThe dispute letter with each item's evidence, the sign-off checks, and the short-pay instruction to accounts payable.
Co-signature above the limitA $412,800 gate-charge dispute at the hub, citing the lease, routed to the Airport Affairs Director to co-sign.
When the agents disagreeThe checker and the Verifier read an emissions class differently; both workings are kept and a person chooses.
Airport invoice readingBills in any format read into lines with a confidence per field; a smudged passenger count goes to a person, a locked file to the station.
Route charges auditAir navigation charges validation: each flight recomputed from the route flown — billed against flown kilometers, a duplicate flight and filed-route billing.
Credits tracked to cashEvery dispute from sent to credited, with reply clocks, drafted chasers and credit memos matched to their disputes.
Audit trailEvery agent step and every person's decision in order, each entry sealed to the one before, exportable as evidence.
Thresholds and rulesDispute threshold, automatic release, reading confidence, co-signature limit and the rules the agents follow, tested on last month.
Governance

Built for supplier invoice audit: two agents agree, a person signs, every step on the record.

Two agents must agreeThe Verifier re-derives every finding from the records without seeing the first working. Nothing reaches the analyst on one agent's word, and a disagreement goes to a person with both workings.
A person decides and signsThe analyst approves, edits or rejects every finding and signs every dispute with a reason code and a signed statement. Above $50,000 the Airport Affairs Director co-signs.
Agents never decide, pay or write offThe agents draft letters, chasers and corrected fleet files; nothing leaves the airline until a person approves and signs it. Accounts payable alone releases payments, and agents never change a register or a tariff.
Every value cites its sourceEach finding and each agent answer links to the invoice line, the ACARS record, the weight certificate or the tariff clause it rests on — one click opens the passage.
Our own errors looked for firstBefore blaming the airport, the agents check Corvane's own fleet file, schedule and reported passenger counts, and the dispute letter owns the airline's mistakes.
A chained audit trail and evidence packsEvery agent step and every person's decision is recorded in order, each entry sealed to the one before it. Evidence packs export for the airport and for internal control reviews.
Configuration

Your thresholds and rules, not ours

How the audit runs is a setting. Every change is signed, logged and tested on last month's bills before it takes effect.

SettingDefaultChoose from
Dispute a line when it differs by more than$25Any amount; re-tested on last month before saving
Release a clean bill to AP on its own under$2,000,000Any amount; only when every line ticks
Ask a person when a field is read below92% confidenceAny percentage
Co-signature above$50,000Any amount; the Airport Affairs Director co-signs
Landing weight used for pricingCertificated maximum landing weight from the weights registerOn or off
A movement did not happenOnly when two independent sources agreeOn or off
Check every bill within3 business days of receiptAny number of days
Raise a dispute · draft a chaser10 days before the window closes · after 30 days without a replyAny number of days
Connections

Works with the records an airport bill is checked against

Airport and navigation invoicesIATA SIS supplier e-invoices, PDFs by email, airport portal files and scans
Flight operationsflight records with OOOI and ACARS times
Airport movement datathe airport's own arrivals and departures, where it is shared
Aircraft weights registercertificated landing and takeoff weights per tail, from the flight manuals
Tariffs and agreementsrates and charges, rate letters, use agreements and leases
Accounts payable ledgerpayments, holds and credit memos
What it changes

The difference, in numbers.

Every figure is labelled: a target the solution is built to, an estimate, a typical published result, or a proven one.

estimated
$18M
at stake on a $500M airport bill at a 3.6% re-keying error rate
target
100%
of invoice lines checked against flights, weights and tariffs, not a sample
every line
ticked and verified
target
90%
of disputed value credited within 90 days, tracked to cash
90% credited
within 90 days

“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, via Symphony Solutions — airport and air navigation charges 15–16% of air transport costs, and a 3.6% re-keying error rate; San Francisco Controller audit 05031, 2006 — landing fees per 1,000 lb, and 393 landings reported at the wrong weight). Corvane Airways, Halvard Air, the people, flights, tails, invoices and rates named on this page are fictional — characters and sample data in the working solution.

Questions

What airline finance teams ask about an airport charges audit.

What is Airport Charges Audit?

Airport Charges Audit is an airport charges audit run by AI agents: it checks every airport and air navigation charge against the flights the airline flew, the certificated weight of the tail that flew and the tariff in force that day. It replaces the sampled airport charges reconciliation done in spreadsheets with airport invoice validation of every line: eight agents read each bill in any format, tick every line, re-derive each finding independently and draft the dispute; the airport cost analyst approves and signs, and the credit is tracked to cash.

How does a landing fee audit check aircraft weight?

At US airports, landing fees are billed per 1,000 lb of maximum gross landed weight, so the Weight and tariff checker re-prices every landing from the FAA-certificated weight of the tail that flew, taken from the weights register, and the rate in force on the movement date. In the working solution it found six landings of a 787-9 billed at 777-300ER weight — 554,000 lb billed against 425,000 lb certificated, $4,775.58.

Does it catch diverted and canceled flights billed as landings?

Yes. The Movement matcher ticks each billed movement against the airline's flight records with OOOI and ACARS times and the airport's movement data. A movement is treated as not having happened only when two independent sources agree, and ferry or positioning landings that really happened stay billable.

How are air navigation route charges validated?

The Navigation charge checker recomputes each flight from the route actually flown, the weight factor from the takeoff weight and the provider's unit rate. In the working solution it recomputed 1,186 European route-charge flights and found one billed twice and six billed on the filed route instead of the shorter route flown; on the Canadian bill it found two 787-9s charged with a 777-300ER MTOW weight factor.

How do we dispute an airport invoice and make sure the credit arrives?

The Dispute drafter writes the letter citing the agreement clause and each line's evidence, with a short-pay instruction for accounts payable and an evidence pack. After a person signs, the Credit tracker watches the airport's reply clock, drafts chasers before it lapses and matches the credit memo to the dispute when it lands on a later bill.

Does the AI send letters, pay invoices or change our records?

No. The agents draft and recommend; nothing goes to an airport until a person signs it, and they never pay, write off, or change a register or a tariff. A person approves, edits or rejects every finding and signs every dispute with a reason code, and disputes above $50,000 need the Airport Affairs Director's co-signature.

Can we set our own thresholds and rules?

Yes. The line threshold for a dispute, the automatic release limit, the reading confidence, the co-signature limit, the rules the agents follow and the clocks for checking, disputing and chasing are all settings. Each change is signed, logged and tested on last month's bills before it takes effect.

How long does it take to go live?

The Agentic Solution Engine builds and deploys it from your requirements and documents — your use agreements, tariffs, weights register and a sample of past airport and navigation invoices — and it goes live once every quality gate has passed. We will walk you through it on your own bills first.

See it on
your airport bills.

We'll run Airport Charges Audit on a sample of your own past airport and navigation invoices.