Iberia is to move its services from Heathrow into sister carrier British Airways’ state-of-the-art Terminal 5 from the start of the summer flying schedule.
The move from March 25 will improve connections between the two airlines' networks.
The minimum connection time between Terminal 5 and Terminal 3 (currently used by Iberia) of 90 minutes is expected to reduce to 60 minutes.
The move to Terminal 5 will also strengthen code share arrangements on many flights.
The Spanish carrier said it was using all communications channels to inform passengers and travel agents of the change, including information pillars in Terminal 3.
Business-class passengers will benefit from special check-in areas and fast-track security control procedures.
Iberia and BA flights have been located together at Madrid’s Barajas airport Terminal 4 since it opened in 2006. All flights between the two hubs will leave from the same terminals from next month’s switch over date, giving passengers a much smoother transfer experience between flights, Iberia claims.