Part 1 - Pricing Fundamentals

This series of articles will go over some advanced fare hacks that can be used to improve you flight iternary and add some fun side trips when purchasing flight tickets. For the sake of simplicity, I assume you have already have heard / used the tools listed below:

Across these series of articles, I will use ExpertFlyer to check the flight availability and fare rules, and use ITA Matrix to validate the pricing. FlightConnections will be used to check availability flight routes for any airline.

Basics

Before we try to apply any hacks, we should review the basics on how do airlines determine the price of you flight iternary.

Essentialy, it's based on the following two things.

Availability of Fare Classes
Fare Rules

Availability of Fare Classes

Airplanes have limited capacity. Based on the principles of economy, an airline that operates the airplanes would highly likely wants to maximize the profitability by providing different classes of services in different cabins at different prices. To represent such a concept, a term called fare class (booking code) has been used. If you ever played with any frequent flyer programs, you may know that different fare class may accumulate milages / points at different rates due to the different price buckets (i.e. levels of revenue to the airline) associated with each fare class.

Take United Airline as an example (only some are shown):

Fare Class	Cabin	Meaning
N	Economy	Basic Economy
Y	Economy	Full Fare
R	Premium Economy	Deep-discounted Premium Plus
Z	Business	Discounted Business

Table 1. United Airline Fare Classes

If we use ExperFlyer to search for flight availability, we can get detailed availabilities of each fare classes (inventory).

Airline can control the availabilities of each fare classes (inventory) in order to make the auto-pricing system to match different fare rules (more details later) and eventually achieve dynamic pricing based on market demand, competition and etc.

Fare Rules

Fare rules are a set of rules that deterimines the price of your flight iternary defined by an airline company. They may contain rules on which flight you can take, which fare class you must use, the routing of your trip, penalties for changing and refunding your tickets and etc. To apply the fare hacks, we should focus on the following parts of the fare rule:

Category 4: Flight restrictions
Category 8: Stopover restrictions
Category 9: Transfer restrictions
Category 10: Combinability
Routing Restrictions
Booking Class Table for other airlines (for interline only)

Airlines can also control the prices and rules of each fare rule in order to achieve dynamic pricing.

Advanced Concepts

Fare Component & Pricing Unit

A typical flight iternary usually contains multiple segments. For each segments, it is refered as a fare component. A fare rule covers the pricing for one or more fare component and these components are called as a pricing unit. A flight iternary may contains one or more pricing units in order to come up with the overall pricing for all segments.

Type of Trips

One Way

flowchart LR
  PEK --> ICN

Round Trip

flowchart LR
  PEK --> ICN
  ICN --> PEK

Open Jaw

flowchart LR
  PEK -- Outbound --> ICN
  ICN ~~~ PUS
  PUS -- Inbound --> PEK

or...

flowchart LR
  PEK -- Outbound --> ICN
  ICN -- Inbound --> PVG
  PEK ~~~ PVG

Double Open Jaw

flowchart LR
  PEK -- Outbound --> ICN
  ICN ~~~ PUS
  PUS -- Inbound --> PVG

Circle Trip

flowchart LR
  PEK --> ICN
  ICN --> PUS
  PUS --> PEK

or...

flowchart LR
  PEK --> ICN
  ICN --> PUS
  PUS --> PVG
  PVG --> PEK

Type of Combination

As mentioned above, a typical flight iternary can contains multiple fare rules combined together. For each pricing unit, it may contains different type of trips shown below:

End-on-End

flowchart LR
  ICN ~~~ PUS
  subgraph "Fare Rule 1"
  PEK --> ICN
  end
  subgraph "Fare Rule 2"
  PUS --> PVG
  end

Side Trip

flowchart TB
  HKG --> ICN
  ICN --> PEK
  subgraph "Side Trip"
    ICN -.-> CJU
    CJU -.-> ICN
  end

Fare Rule 1 covers:

HKG ICN PEK

Fare Rule 2 covers:

ICN CJU ICN (Side Trip)

Surface Sector

A segment that is not travel by air and uses other mode of transportation like bus and rail.