Emirates has upgraded its daily Boeing 777-300ER service from Heathrow to Dubai to an Airbus A380, adding more than 150 seats a day.
The change means all nine flights on Emirates out of London will be operated by the wide-body aircraft.
Laurie Berryman, Emirates vice president UK, said: “We launched our first service to Heathrow in 1991 and since then demand for travel from London to Dubai and beyond has seen tremendous growth.
“In the last 25 years we have carried over 20 million passengers on the route.
“The addition of a sixth daily A380 means that all of our flights from London are now operated by this hugely popular aircraft, and allows us to carry even more customers in the most comfortable and efficient way possible.
“The change means that Emirates can now carry up to nearly 3,000 passengers from Heathrow to Dubai each day.
“As the economies of both London and Dubai continue to grow, we’re confident that the next 25 years will be just as successful as the last, as we continue to connect people and businesses across the globe.”