As many will be aware, the through running of Elizabeth line trains at Paddington and Liverpool Street begins this Sunday (6 Nov).
For journeys between the west section (west of Paddington) and the east section (east of Liverpool St) customers will have to interchange somewhere in the central section.
TfL are recommending customers do this at Whitechapel as the station has wide platforms and all trains call at Whitechapel. In contrast, for example, Paddington has narrower platforms which are more cluttered with station furniture, so there is a risk of overcrowding if everyone gets off at Paddington.
TfL Journey Planner API will be giving Whitechapel as an interchange for such journeys, but for any routing apps not using the Journey Planner API, please consider defaulting to a Whitechapel interchange, as we believe that would give the best experience for customers.
Any questions let me know, thanks!