Joining Simplified Invoicing and Settlement (SIS) instantly connects you with more than 420 airlines and intermodal entities exchanging interline billing data electronically. SIS eliminates the paper from the interline billing and settlement processes increasing efficiency and reducing costs; it enables processing automation which helps reduce billing duplication and simplifies reconciliation.

Who can join SIS for interlining?

All airlines (IATA and Non IATA Members) and their intermodal partners are eligible to become SIS participants under the "SIS for Airlines & Intermodal" program. This membership covers all 4 submission classes: Passenger, Cargo, UATP and Miscellaneous/Non-Transportation. The participation fees incurred under this model are variable, based on budgetary expectations of operating cost, and vary according to the size and status of the participant (larger, smaller, etc.; IATA, non-IATA, etc.). This is the core agreement for SIS Participation and includes governance rights such as the ability to vote for changes to the standard industry agreement terms, or to vote for changes to functionality at the SIS General Meeting.

A sample of the "Standard Agreement for SIS Participation" (pdf) is available for information purposes only, not for signature. The costs of using SIS under this program are outlined in Attachment A (pdf) of the agreement.

Please refer to the user guide (pdf) on how to access the forms and submit an application using the IATA Customer Portal.

Documents required for joining

  • Joining checklist (pdf)
  • Online application form submitted via the IATA Customer Portal
  • Standard Agreement for SIS Participation signed by a Company authorized representative
  • Corporate Documents
    • Company Registration/Articles of Incorporation
    • Ownership structure including passport copies of all owners/shareholders
  • Bank Details (Optional) (pdf)

If you plan to submit billings to SIS via IS-IDEC or IS-XML files (pdf), prior testing and certification will have to be done. Guidance for testing and minimum requirements for certification are provided in the "Sign up and certification guide " (pdf).

To see which of your business partners are already using SIS, please download the SIS member list (xls).

Connect to ICH for Settlement  

The IATA Clearing House (ICH) provides settlement services for the air transport industry. It enables the world's airlines and industry suppliers to settle their Passenger, Cargo, Miscellaneous/Non-Transportation and UATP billings by ap​plying the principles of off-set and netting. The ICH also offers protection in the event of a payment default and/or bankruptcy.

For more information, please visit How to join ICH

Sign-up & Certification Guide

The Sign-up and Certification Guide (zip) provides details on the steps required for joining SIS. It defines various processes such as Member Profile Set-Up, Connectivity Testing, Sandbox/Certification Testing, and an overview of the IS Participation Agreement.

The Sign-Up and Certification Guide also contains the Super User form (Annex 1) and Bilateral Bank Details Form (Annex 2). As part of the requirements to join SIS, the Super User form must be completed. Bilateral Bank Details form is optional and applicable only for bilateral settlement invoices.

User Guide

The User Guide​ (zip) is an extensive manual to help SIS users navigate through the various screens on the SIS platform. This document describes in detail all screens and fields available on IS-Web and how to use them appropriately.

Computer-Based Training (CBT)

The Computer-Based Training (CBT) is a set of web tutorials aimed at providing users an overview of how to use the SIS platform. The tutorials present available functionalities that are accessible by an IS-Web user.

Reference Documentation

The following are various support documents related to implementing SIS.

Integrated Settl​eme​nt Participation Guide (ISPG)

The ISPG contains all information and specification needed in order to fully implement Integrated Settlement (IS). This document is revised from time to time as needed.

IS-IDEC Record Structure

IS-XML Record Structure

Sample Files

Supporting Attachments

ICH Reports ​​

Production System Release Notes

These notes include important information regarding changes deployed in the SIS live environment.​​​​​​​​​​

Maintenance Release​s


Major Releases​



ACH (Airlines Clearing House) – The A4A clearinghouse for electronic invoicing.

Accounting Code - This code is meant for transport documents; this number is used on tickets as the first three characters of the ticket number. The same number can be used for cargo documentation and is known as an "airline prefix".

AIA - (ATPCO, IATA, ARC) – AIA is the organisation formed by ATPCO, IATA, and ARC to support the First & Final™ process.

Air Operator The actual air carrier that operates the flight.

Ancillary Products & Services - Products and services that are meant to enhance a customer's travel experience beyond the sale of air transportation tickets. They may include items such as baggage fees, on-board food, loyalty or premium products and services, and so much more.

ARC (Airlines Reporting Corp.) – ARC operates COMPASS® which houses transaction and prorate data for the purposes of settlement.

A4A (Airlines for America) – The trade group for U.S.-based airlines.

ATPCO – ATPCO, amongst other services, operates the Sales Exchange process whereby sales for First & Final™ transactions are extracted, prorated, and sent to the uplifting carrier.

Auto-Billing – A feature of SIS whereby a billing carrier is able to submit a list of uplifts. SIS will then find the prorate (either a stored own prorate or an NFP) and create the necessary billing, settlement, and invoice files. A pro-forma invoice is sent to the billing carrier daily, and invoices are sent to the billing and billed carrier on settlement.


BSP (Billing and Settlement Plan) – An IATA service for the settlement of ticket revenues between agents and carriers. BSP fees can appear on electronic invoices. More information on BSP

BIETA;Bilateral Interline E-ticketing Agreements - The IATA Bilateral Interline E-Ticketing Agreements (MITA) publication that provides all the passenger and cargo bilateral E-ticketing interline agreements. BIETA outlines the bilateral agreements whereby passengers and cargo use a standard traffic document (i.e. passenger ticket or air waybill) to travel on various modes of transport involved in a routing in order to reach a final destination.

Billing Memo -An authorized debit transaction from one invoicing member to another using appropriate source and billing codes.

Block Chain - Is a decentralized and digitized public ledger of all crypto-currency transactions. Completed transactions are recorded as an “added block” to the chain in chronological order, it allows participants to keep track of digital currency transactions without central recordkeeping


CDA (Call Day Adjustment) –An adjustment based on the difference between the exchange rates of Miscellaneous items as submitted to the ICH and the exchange rate used on Call Day.

CH (Clearinghouse) – The general term and acronym for a clearinghouse, whether the ACH or ICH.

Charge Category -Distinguishes the broad category of services being billed on an invoice. Used by the recipient to decide which IT system or department needs to receive the invoice (work flow). For e.g.: Ground Handling, Engineering etc.

Charge Code -Distinguishes the broad category of services being billed on an invoice. Used by the recipient to decide which IT system or department needs to receive the invoice (work flow). For e.g.: Ground Handling, Engineering etc.

Charge Code Type -Specifies further the nature of the service, is equivalent to a standardized productID

Credit Memo - An authorized credit transaction from one invoicing member to another using appropriate source and billing codes.

Correspondence - Once the rejection cycle is over and the dispute on the billing is not settled, the entity receiving the last Rejection invoice can initiate a Correspondence to pursue the case further. The process of Correspondence is managed via IS-WEB and this will be the only medium available to the billing/billed entities to communicate.

CRAS - Cargo revenue Accounting system


Digital Signature – A digital signature is analogous to its analog namesake and proves two things: that the claimed party generated the document, and that the document was not altered after being signed. Digital signatures are required on electronic invoices in some countries.

Dispute - The action of challenging a received billing on the basis of incorrect data or billed values. May also be considered a "Rejection", "Rebill", or "Recharge".

Designator Code -Airlines as well as railway, bus and ferry companies, computer reservations systems (CRSs) and ULD owners/leasing companies may be assigned an IATA two-character designator code.


E-AWB (Electronic Air Waybill) – The electronic representation of the cargo air waybill. More information on E-freight

EBT - Excess Baggage Ticket - ticket issued for the transport of excess baggage, may include interline carriers.

EDIElectronic Data Interchange - Electronic data interchange is the concept of businesses communicating electronically certain information that was traditionally communicated on paper.

Electronic Presentation – A term used to specify a supporting document that is digital but not in a defined and structured format. The document might be a PDF file or an image that a computer can read but not extract data from. Similarly, a copy of the Revenue Accounting Manual could be pasted into Excel but would be useless to a computer trying to parse specific values.

E-Electronic Document – A term used to specify that the supporting document is in a defined and structured format which can be parsed by a computer. Example formats are XML or CSV.

E-Invocing - Electronic invoicing (also called e-invoicing) is a form of electronic billing. E-invoicing methods are used SIS billing members to present and monitor transactional documents between one another and ensure the terms of their trading agreements are being met.

EMD - Electronic Miscellaneous Document - The Electronic Miscellaneous Document (EMD) is an International Air Transport Association (IATA) standard for electronically documenting ancillary revenue; that is, all other sales and transactions between airlines and passengers besides electronic tickets.


F12 – The file that a carrier uploads to the IATA Clearing House (ICH) on a weekly basis to complete settlement. This file does not contain all billing data; rather it contains the totals of each invoice being cleared.

FDR - Five Day Rate - This exchange rate represents the average of the exchange rates for the five banking days ending on the 25th of each month. This calculation is based on the average between the buying and selling rates and the rates are expressed in USD, EUR, and GBP. FDR's are used by ICH members to convert interline billing into the billing currency. The previous month's FDR's are used for the current month's interline billing.

F&F (First & Final) – Process in which two carriers agree to use a Neutral Fare Proration engine for electronic invoices. In agreeing to settle on a First & Final basis, they are also agreeing that rejects based on prorate values are not permitted.


GDS (Global Distribution System) – The services through which travel agents can book tickets. GDS charges can appear on electronic invoices.

GSA (General Sales Agent) – The carrier sales representative for a given region or location. GSA services, when provided by one carrier to another, are charged over a Miscellaneous invoice.


ICH (IATA Clearing House) – The IATA clearinghouse for electronic invoices. More information on ICH

IS (Integrated Settlement) – Integrated Settlement is the name for the collection of systems which provide the functionality behind Simplified Invoicing and Settlement (SIS). For more information, see SIS page.

Intermodal - Intermodal transport (or intermodal transportation) involves the use of more than one mode of transport for a journey.

INV- Involuntary Reissue/Reroute - A scenario where the transporting carrier is unable to fulfil its scheduled operating flight and the passenger e-ticket must be reissued/rerouted onto the same or a partner carrier to complete the journey.

IS IDEC -Integrated Settlement - Interline Data Exchange Centre. A file type supported by SIS and most Revenue Accounting System used to submit or receive interline billing transactions in SIS.

ISO 27001-ISO 27001 -(formally known as ISO/IEC 27001:2005) is a specification for an information security management system (ISMS). An ISMS is a framework of policies and procedures that includes all legal, physical and technical controls involved in an organisation's information risk management processes.

ISPA - Integrated Settlement Participation Agreement

ISUA - Integrated Settlement User Agreement

IS-XML - Integrated Settlement - Extensible Markup Language. A file type supported by SIS and most Revenue Accounting System used to submit or receive interline billing transactions in SIS.


Legal Archive - This is an optional service offered by SIS to maintain member's billing transactions live in SIS Production environment for up to ten years. Refer to the SIS Pricing Schedule for details.

Location ID - Used to identify a specific location area (branch) or department that is used for specific billing and/or taxation purposes.


Miscellaneous P Item – A “P item” is related to a passenger invoice. A Miscellaneous P Item can be charges for such things as codeshare commission and Flight Interruption Manifests (FIMs).

MRO (Maintenance/Repair/Overhaul) – Aircraft maintenance services that are sometimes performed by one carrier for another and then charged via an electronic invoice.

MITA - Multilateral Interline Traffic Agreement - Multilateral Interline Traffic Agreement - The IATA Multilateral Interline Traffic Agreements (MITA) is publication that provides the passenger and cargo Interline Agreements that spell out which airlines have agreements and the basic rules airlines follow when processing revenue and issuing documents for carriage on each other’s services. It outlines the multilateral agreements whereby passengers and cargo use a standard traffic document (i.e. passenger ticket or air waybill) to travel on various modes of transport involved in a routing in order to reach a final destination.

MPA - Multilateral Prorate Agreement - Participating MITA concurrence members are subject to the Multilateral Prorate Agreement (MPA) rules which calculates the revenue share per flight coupon on a ticket and as a result the value an airline will receive for carrying an interlining passenger on any given journey segment.


NDC - New Distribution Capability - This is a travel industry-supported program (NDC Program) launched by IATA for the development and market adoption of a new, XML-based data transmission standard (NDC Standard). The NDC Standard enhances the capability of communications between airlines and travel agents.

NFP (Neutral Fare Prorate) – A prorate created by a “neutral” party, as currently used within First & Final™ settlement. Because of their neutral nature, NFPs are less likely to get rejected by the billed carrier, even outside of First & Final™. In the future, NFP values will be available to all carriers that wish to use them.

  • Final – Final NFP values will be similar to First & Final™ and supported by an agreement between the carriers stating that Final NFP values cannot be rejected.
  • Non-Final – Non-final NFP values are not supported by a bilateral agreement and can be rejected in case of dispute. Non-final NFP values offer the benefit of a lower likelihood of rejection.


OAL - Other Airline

ONE Order - ONE Order is the concept of a single Customer Order record, holding all data elements obtained and required for order fulfilment across the air travel cycle - such as customer data, order items, payment and billing information, fulfilment data and status.​


PRAS - Passenger Revenue Accounting System

PAT-GRO - Passenger Air Tariff-General Rules Online - Online resource that provides ticketing rules and taxes, fees, and charges applicable to all carriers and countries.

Payment Status - A feature available on SIS allowing members to update the payment status of bilateral miscellaneous billing transactions.

PRAS - Passenger Revenue Accounting System - processing system for passenger revenue accounting transactions.


RAM (Revenue Accounting Manual) – The RAM is where most rules related to revenue accounting are documented. More information on RAM

Recap Sheet - the equivalent of the F12 - i.e. the file that a carrier uploads to the Airlines Clearing House (ACH) on a weekly basis to complete settlement. This file does not contain all billing data; rather it contains the totals of each invoice being cleared.

RATD - Revenue Accounting Tax Database - derived from the Ticket Tax Box Service, the RATD reflects the amounts to be collected and remitted for interline tickets.

RM - Rejection Memo - A recharge or rebill transaction from one invoicing member to another using appropriate source and billing codes.


SIS (Simplified Invoicing and Settlement) – Simplified Invoicing and Settlement is the name of the electronic invoicing platform. See the introduction for more information.

Smart Contract - Is essentially digital protocol intended to enable, validate, and administer the negotiation or performance of an agreement

Stored Own Prorate – A sales carrier will have the ability to upload prorated fares to Integrated Settlement and specify who may download those fares. Integrated Settlement will then store the prorates, at which point they are considered “stored own prorate”.
Optionally, the sales carrier may specify that the prorates are not to be stored but only switched, in which case they’re sent directly to the planned uplifting carrier.

SDF - Supporting Documents File - zipped file containing all supporting documents associated to submitted billing transactions in SIS.

SOC2 - Certification of Controls at a Service Organization Relevant to Security, Availability, Processing Integrity, Confidentiality or Privacy.

SPA - Special Prorate Agreement - bilateral prorate agreement between interline partners that supercedes the Multilateral Prorate Agreement.


TOU - Terms Of Use - Free of charge SIS membership that allows for receipt of non-transportation invoices only. This membership does now allow for the submission of any invoices to interline partners.

Ticketless Process - This is the process of selling airline seat inventory and maintaining customer reservation records without the need for a paper or electronic ticket. This process or model is more readily adopted by low-cost carriers and allows for interlining with other carriers.


ULD Demurrage - The charges due to the owner of a Unit Load Device (ULD container) where the carrying airline has not returned it to the owning airline within the allowed time.


XML (eXtensible Mark-up Language) - A structured file format similar to HTML as used in websites, which includes tags that indicate the meaning of content. For example, a tag <invoice_number> would specify that the invoice number follows. These tags allow for a more fluid document that does not rely on fixed positioning of data (as occurs in the IDEC format).


Who is eligible to join?

Any airline is eligible to join SIS, whether or not they are a clearing house member.

Non-airlines may also join SIS provided that they do business with airlines. It is now​ possible for non-airlines to do business with other non-airlines through SIS.

How do I join SIS?

Access to SIS is granted once the Integrated Settlement Participation Agreement has been signed and the participant has passed the necessary certification process. This process is detailed in the Sign-Up Guide. These documents will be made available in the Join SIS tab above.

How do I know when my e-Invoicing partners are migrating to SIS?

Airlines’ migration plans will be shared on a permission-basis. In the SIS Forums, there is a designated place where planned migration dates of airlines are stored. This information is released to the parties that are willing to share their own migration plans with us and their fellow carriers that have access to the list. For more information regarding this, please contact us via the IATA Customer Portal or download the SIS Member List for the updated list of active SIS members.

What are the charge​s of using SIS?

SIS is run on a cost-recovery basis. These charges will be specified in your Integrated Settlement Participation Agreement. An updated sample of the pricing schedule can be found here.


Signing Up & Migration Steps

What are the key submission options for SIS?

One of the many benefits of SIS is that interline partners will no longer depend on each other when it comes to choosing the formats to submit files. Under SIS, participants may select among various formats to submit files and this will not affect the way their billed entities receive the files.

The three submission options are IS-IDEC, IS-XML, and IS WEB (manual input via web interface).

A matrix outlining the possible options to submit files/invoices can be found in the Integrated Settlement Participation Guide (ISPG) Chapter 2.3.

What is the Sandbox?

The Sandbox is a dedicated separate environment primarily having the SIS validation components. The purpose of the Sandbox is to ensure that the outputs generated by your individual revenue accounting systems are as per the requirements of SIS.

In the Sandbox, you will be able to upload SIS format files (IS-IDEC and IS-XML) without any restriction on the number of files. SIS will validate your input file (IS-Validation) and will also check if the minimum certification requirements are met. Further details on the Sandbox are specified in the Sign-Up and Certification Guide.

How can I learn about using SIS?

Various training materials will be made available prior to go-live. These include:

a. Computer-Based-Training (CBT)

b. User Manual

Information on these materials will be described on the Support tab.​

​​ ​

Technical Aspects​

Can formats of invoices be mixed? e.g. IS-XML for one Charge Code and IS-Web for another Charge Code?

Yes. SIS offers the flexibility for all invoices submitted in any format to be viewed in IS-Web. Please also refer to the ISPG Chapter 2.3 for more information on the overall flexibility of file transmission choices.

How will the Call Day Adjustments (CDA) operate with SIS?

The ICH will generate CDA invoices as now and will create an IS-XML file (Charge Category: Service Provider / Charge Code: CDA) on the initialization of Clearance Period 2. Additional to today, the IS-XML file will also provide details of original invoices included in the CDA to simplify reconciliation of CDA amounts and enable allocation of any adjustment to the original invoices. As the invoice number format used by the ICH today exceeds the number of characters available in SIS, the number format will be changed to: "CD" + YY (invoice year) + MM (invoice month) + XXXX (incremental number), e.g. CD10080023 would identify the 23rd CDA invoice generated for August 2010.

What are the costs associated with using iiNet?

For the basic file transfer functionalities to/from SIS, no transaction fees will be applied. The access to iiNet using a manual account will also be free of charge. Participants wishing to set up a new automated file transfer account would be charged the current iiNet fees. Any optional iiNet functionalities beyond the basic file transfer, will be subject to iiNet current fees. For further information, please contact iiNET via the IATA Customer Portal.

SIS Bulletins ​

Subscribe to SIS bulletins​ by logging a request through the IATA Customer Portal.


e-Invoicing FAQ​ (pdf)​​​​​​​​

Passenger Rejection Reduction Initiative   imagedr6fv.png

One of the key actions of the IATA Financial Committee is to improve efficiency in airlines back office processes. Improvement is required in the area of Passenger interline billings, where more than one million rejections are raised per month. The Interline Billing and Settlement (IBS OPS) Working Group has been tasked to improve efficiency by cutting down on incorrect rejections via education, awareness, proposing changes to the billing rules, and adding new validations in SIS.

The charts below illustrate the count and USD amount of rejections over the past five years.

RM Count - 2019.png
RM Value (USD Mil) - 2019.png


Progress Reports

For billings following IATA RAM rules

2020 2019 2018 2017 2016
January 2020 (pdf) Annual Report (pdf) Annual Report (pdf) Annual Report (pdf) Annual Report (pdf)
February 2020 (pdf) January 2019 (pdf) First Quarter (pdf) First Quarter (pdf) First Quarter (pdf)
  February 2019 (pdf) Second Quarter (pdf) January 2017 (pdf) Second Quarter (pdf)
  First Quarter (pdf) January-February 2018 (pdf) February 2017 (pdf) Third Quarter (pdf)
  April 2019 (pdf) April 2018 (pdf) April 2017 (pdf)​ April 2016 (pdf)
  May 2019 (pdf)     May 2016 (pdf)
  Second Quarter (pdf)     July 2016 (pdf)
  July 2019 (pdf)     August 2016 (pdf)
  August 2019 (pdf)     October 2016 (pdf)
  Third Quarter (pdf)     November 2016 (pdf)
  October 2019 (pdf)      
  November 2019 (pdf)      

Rejection Reduction Best Practices

Click here (pdf) to access the Rejection Reduction Best Practices document.



Webinar Presentation (pdf) - March 2019

Webinar Q&A Report (pdf) - March 2019

​2016 ​WFS PAX Rejection Memo Reduction

2017 ACH Annual Meeting



SIS Bulletins

On this page you will find all industry presentations relating to SIS and the most recent issues of the SIS Bulletin.Subscribe to SIS bulletins​ by logging a request through the IATA Customer Portal.


Issue 11 (pdf) October

Issue 10 (pdf) September
Issue 9
(pdf) September
Issue 8 (pdf) July
Issue 7 (pdf) May

Issue 6 (pdf) April
Issue 5 (pdf) March
Issue 4 (pdf) March
Issue 3 (pdf) February
Issue 2 (pdf) February
Issue 1 (pdf) January

Previous SIS Bulletins

2019 SIS Bulletins (zip)

2018 SIS Bulletins (zip)
2017 SIS Bulletins (zip)
2016 SIS Bulletins (zip)
2015 SIS Bull​etins (zip)​
2014 SIS Bulletins (zip)

COVID-19: SIS Updates

Below are important SIS updates.
30-October-2020 (pdf)
08-October-2020 (pdf)
26-August-2020 (pdf)
30-July-2020 (pdf)
20-July-2020 (pdf)
09-July-2020 (pdf)
23-June-2020 (pdf)
16-June-2020 (pdf)
03-June-2020 (pdf)
21-May-2020 (pdf)
14-May-2020 (pdf)
24-April-2020 (pdf)
16-April-2020 (pdf)
30-March-2020 (pdf)

World Financial Symposium (DXB) 2020 - Canceled

6th IBS OPS & 9th SIS Annual General Meetings


2020 industry meetings were reduced in scope to live online webinars. Below are the links to the live recordings, presentation slides, and answers to the questions related to these webinars.

IBS OPS WG 2020 Webinar - 28 September 2020

Below are the reports available for the IBS OPS WG 2020 Webinar.

SIS 2020 Update Webinar - 29 September 2020

Below are the reports available for the SIS 2020 Update Webinar.

Previous SIS General Meeting Presentations


Webinar #02-2020: SIS Miscellaneous Billings & Best Practices.


Webinar #01-2020: New SIS Functionalities -What you should know!

Webinar #01-2019: New SIS Functionalities - Are you making the most of them?

Legal Archiving



Payment Status


CSV Invoice Update


Location ID