Interchange occurs between London Underground, main line and international rail, and bus services. The interchange zone is also a gateway to the local area with destinations that include the British Library.

St Pancras International is a landmark station, providing airport-like facilities and a high quality built environment. The station design sensitively integrates heritage elements, such as the original barrel roof with a modern aesthetic. An underground ticket hall connects Kings Cross Underground Station to St Pancras International via the western concourse. Interchange from King's Cross main line to St Pancras is on street level. Works are currently underway to upgrade King's Cross Station to improve the passenger environment and improve connectivity across the interchange zone. These works will also include secure cycle parking facilities.

The open, bright design, general cleanliness and high-end retail outlets of St Pancras International create a positive sense of arrival for passengers and have resulted in the station acting as a destination in its own right. Movement paths within the interchange facility are largely direct and clear with good sight lines and little clutter. Spatial management is good with mixed use spaces arranged to either side of movement spaces, decision points are relatively clear with minimal advertising or other distractions. Much of the station environment is step-free with lifts, where needed, located on desire lines. A visible staff presence, combined with pedestrian and retail activity promotes a sense of safety and security.

Issues that impact on the effectiveness of the interchange include; a lack of legibility from the main concourse to some services; some conflicts between movement and mixed use spaces and inconsistencies of signing across the interchange facility.