Quote Filtering and Selection

Routes Configuration

Each of Skyscanner's Partners can be configured to be priced on a specific subset of searches. This configuration mechanism is highly flexible and can take into account high-level factors such as:

• Traveller's market
• Origin/destination countries
• Type of search: e.g. one-way, return, multi-destination
• Number of passengers
• Travel dates
• Qualification based on a specific carrier’s timetable

For further details on these configuration options, please speak to your Skyscanner Commercial Manager or reach out to Partner Services.

Post Processing

Skyscanner filters results received from partners to ensure relevancy and convenience for travellers. These are known as post-processing filters. We apply these to ensure we provide the best and most relevant results to our users. There are several stages of filtering which may alter the results that are finally displayed to the end user on Skyscanner products.

These filters and adjustments are detailed below and are applied in the order shown.

Duplicate Filtering

The quotes returned from a pricing request to a partner are first analysed for duplicates. Currently two quotes are considered duplicates if they have the same departure and arrival airport and times and the same flight numbers and airline identifiers. Once duplicates have been identified, only the cheapest option is retained. All itineraries that have a higher price than the cheapest option are removed.

Cabin Class Filtering

Cabin class is specified as a property of each search. As a result, quotes that do not share the searched for cabin class are deleted from the result. The assigned cabin class for a quote is defined by the cabin class of the longest segment.

Incompatible Time Filtering

The following classes of quotes are removed:

· Where the inbound leg of a return quote is less than 60 mins after the outbound arrival time

· Where the connection time between segments is negative (the subsequent flight departs before the other one arrives)

Commercial Filters (Business Logic)

In some cases, airlines we have a commercial relationship with have requested to be removed from search results of other sources, i.e. travel agents. As such, we remove all of these price quotes from the result set before displaying them on our site in the search results.

The list of these airlines changes frequently so please get in touch with your Skyscanner Commercial contact for more information.

Itinerary Construction

Quotes from multiple partners are combined into a single itinerary with multiple pricing options based on the following properties of the itinerary: departure and arrival airport and times, carrier combinations, via stops and number of stops. During this step, leg-based quotes are also combined into return itineraries.

'Near Duplicate'/'Almost Identical' Itinerary Filtering

This step is designed to remove “near duplicate” itineraries. It is applied in order to improve the relevance of results and the performance of the website, in particular on routes where there are large numbers of indirect itineraries.

The basic principle is that given 2 itineraries that depart or arrive at the same time and are in (almost) all other ways similar, there is no advantage for a user to:

• depart at the same time, but arrive at their destination later
• arrive at their destination at the same time, but depart earlier
• pay more for their ticket

The easiest way to understand the process is to consider an example set of itineraries.

Itinerary ID	Origin	Dep. Time	Stops	No. Of Stops	Carriers	Destination	Arr. Time	Duration	Price
1	EDI	10:20	LHR	1	BA	MAD	13:40	03:20	£400
2	EDI	10:20	LHR	1	BA	MAD	14:20	04:00	£380
3	EDI	10:20	CDG	1	BA	MAD	13:50	03:30	£410

In this example, a user has searched for flights from Edinburgh to Madrid one way and the above 3 itineraries (among others) have been returned to Skyscanner systems. The filtering process works as follows:

1. The itineraries are grouped on the following fields:

• Origin
• Departure Time
• No. Of Stops (note: the actual stops might be different)
• Carriers (note: the order in which the carriers occur during the leg might be different)
• Destination
• Arrival Time

2. This results in the 3 itineraries above being grouped together.

3. Within this group the following itineraries are identified:

• a. The Cheapest Price (Itinerary 2)
• b. The Shortest Duration (Itinerary 1)

4. Any itineraries that are not selected in step 3 are rejected as near duplicates (itinerary 3)

Note also that the cheapest and shortest can be the same itinerary, resulting in all other itineraries being rejected. In the example below, itinerary 1 is the cheapest and the shortest and itineraries 2 and 3 are rejected.

Itinerary ID	Origin	Dep. Time	Stops	No. Of Stops	Carriers	Destination	Arr. Time	Duration	Price
1	EDI	10:20	LHR	1	BA	MAD	13:40	03:20	£400
2	EDI	10:20	LHR	1	BA	MAD	14:20	04:00	£430
3	EDI	10:20	CDG	1	BA	MAD	13:50	03:30	£410

Please also note that "near duplicate" filtering is performed separately for each Skyscanner partner, irrespective of filtering of other Skyscanner results. It is therefore possible that a result filtered out for one partner will not be removed for another, since each provider will have different cheapest and shortest itineraries, and the same logic will be applied to each results set from each of Skyscanner partners.

Relevant Quote Filtering 

During Skyscanner's itinerary construction, itineraries are assigned a relative quality score based primarily on price and duration but also other factors – for example, the need to change airports mid-leg. In cases where there are a substantial number of itineraries returned for a search, a minimum quality score threshold is applied to limit the number of itineraries returned.

Quality Assurance Filtering

Some results are removed because multiple inaccuracies (price inaccuracies, unavailable flights) were observed. You will be informed by our Quality Assurance team if a filter is applied. This filter can be removed as soon as inaccuracies are resolved.

Self-Transfer Filtering

Self-Transfers are flight options which include more than one marketing carrier for a particular leg of the journey. There is a limit of how many self-transfer options are displayed in a result set, based on the aforementioned Quality Score. If certain combinations are classified as self-transfers, some of them might get removed from the result set.

Please also refer to a separate article about this filter: Self-Transfer Filtering 

Maximum results filtering

An upper limit is set for the maximum number of results retrieved for an itinerary search. Depending on the search type, a different maximum will be applied:

• 600 results per journey for one-way and return searches
• 600 results per journey for open jaw searches (searches with 2 legs where the destination and/or the origin are not the same in both directions)
• 500 results per journey for multi-destination searches with 3 legs
• 400 results per journey for multi-destination searches with 4 or more legs

Further cases:

• Where an API request includes cities with multiple airports, we will apply the maximum number of results to each airport pair separately. For example, in a one-way search between London and New York, individual routes (such as LHR-JFK, LHR-EWR, LGW-JFK, etc) will each be allowed the 600 maximum.
• Where an API response contains multiple cabin classes, each cabin class is considered a distinct “journey”, and the maximum will be applied to each individually. For example, if 1000 quotes are returned for a one-way search, with 800 for Economy and 200 for Business, the 600 maximum will be applied to each cabin class separately. So, for a Business search in this case, all 200 results will still be considered.

Quotes from the API response are sorted by price and then parsed, so the maximum cap will always be applied to results with the lowest prices.

Please note that the maximum number of quotes described above is an initial filter on the results returned in the API response. Additional filters may be applied later, which would further reduce the final number of displayed quotes.