A Passenger Name Record (PNR) is a record in the database of a computer reservation system (CRS) that contains the itinerary for a passenger, or a group of passengers travelling together. The concept of a PNR was first introduced by airlines that needed to exchange reservation information in case passengers required flights of multiple airlines to reach their destination (“interlining”). For this purpose, IATA and ATA have defined standards for interline messaging of PNR and other data through the "ATA/IATA Reservations Interline Message Procedures - Passenger" (AIRIMP). There is no general industry standard for the layout and content of a PNR. In practice, each CRS or hosting system has its own proprietary standards, although common industry needs, including the need to map PNR data easily to AIRIMP messages, has resulted in many general similarities in data content and format between all of the major systems.
When a passenger books an itinerary, the travel agent or travel website user will create a PNR in the computer reservation system it uses. This is typically one of the large Global Distribution Systems, such as Amadeus, Sabre, or Travelport (Apollo, Galileo, and Worldspan) but if the booking is made directly with an airline the PNR can also be in the database of the airline’s CRS. This PNR is called the Master PNR for the passenger and the associated itinerary. The PNR is identified in the particular database by a record locator.
When portions of the travel are not provided by the holder of the Master PNR, then copies of the PNR information are sent to the CRSs of the airlines that will be providing transportation. These CRSs will open copies of the original PNR in their own database to manage the portion of the itinerary for which they are responsible. Many airlines have their CRS hosted by one of the GDSs, which allows sharing of the PNR.
The record locators of the copied PNRs are communicated back to the CRS that owns the Master PNR, so all records remain tied together. This allows exchanging updates of the PNR when the status of trip changes in any of the CRSs.
From a technical point, there are five parts of a PNR required before the booking can be completed. They are:
Other information, such as a timestamp and the agency's pseudo-city code, will go into the booking automatically. All entered information will be retained in the "history" of the booking.
Once the booking has been completed to this level, the CRS will issue a unique all alpha or alpha-numeric record locator, which will remain the same regardless of any further changes made (except if a multi-person PNR is split). Each airline will create their own booking record with a unique record locator, which, depending on service level agreement between the CRS and the airline(s) involved, will be transmitted to the CRS and stored in the booking. If an airline uses the same CRS as the travel agency, the record locator will be the same for both.
A considerable amount of other information is often desired by both the airlines and the travel agent to ensure efficient travel. This includes:
In more recent times, many governments now require the airline to provide further information included assisting investigators tracing criminals or terrorists. These include:
The components of a PNR are identified internally in a CRS by a one-character code. This code is often used when creating a PNR via direct entry into a terminal window (as opposed to using a graphical interface). The following codes are standard across all CRSs based on the original PARS system:
The majority of airlines and travel agencies choose to host their PNR databases with a Computer Reservations System (CRS) or Global Distribution System (GDS) company such as Sabre, Galileo, Worldspan and Amadeus.
Some privacy organizations are concerned at the amount of personal data that a PNR might contain. While the minimum data for completing a booking is quite small, a PNR will typically contain much more information of a sensitive nature. This will include the passenger’s full name, date of birth, home and work address, telephone number, e-mail address, credit card details, IP address if booked online, as well as the names and personal information of emergency contacts.
Designed to “facilitate easy global sharing of PNR data,” the CRS-GDS companies “function both as data warehouses and data aggregators, and have a relationship to travel data analogous to that of credit bureaus to financial data.”. A canceled or completed trip does not erase the record since “copies of the PNRs are ‘purged’ from live to archival storage systems, and can be retained indefinitely by CRSs, airlines, and travel agencies.” Further, CRS-GDS companies maintain web sites that allow almost unrestricted access to PNR data – often, the information is accessible by just the reservation number printed on the ticket.
Additionally, “[t]hrough billing, meeting, and discount eligibility codes, PNRs contain detailed information on patterns of association between travelers. PNRs can contain religious meal preferences and special service requests that describe details of physical and medical conditions (e.g., “Uses wheelchair, can control bowels and bladder”) – categories of information that have special protected status in the European Union and some other countries as “sensitive” personal data.”  Despite the sensitive character of the information they contain, PNRs are generally not recognized as deserving the same privacy protection afforded to medical and financial records. Instead, they are treated as a form of commercial transaction data.
On January 16, 2004, the Article 29 Working Party released their Opinion 1/2004 (WP85) on the level of PNR protection ensured in Australia for the transmission of Passenger Name Record data from airlines.
In 2010 the European Commission's Directorate-General for Justice, Freedom and Security was split in two. The resulting bodies were the Directorate-General for Justice (European Commission) and the Directorate-General for Home Affairs (European Commission).
On the 4th of May 2011, Stefano Manservisi, Director-General at the Directorate-General for Home Affairs (European Commission) wrote to the European Data Protection Supervisor (EDPS) with regards to a PNR sharing agreement with Australia, a close ally of the US and signatory to the UKUSA Agreement on signals intelligence.
The EDPS responded on the 5th of May in Letter 0420 D845:
The Article 29 Working Party document Opinion 1/2005 on the level of protection ensured in Canada for the transmission of Passenger Name Record and Advance Passenger Information from airlines (WP 103), 19 January 2005, offers information on the nature of PNR agreements with Canada.