TCS London Marathon to run over two days in 2027
Howard Lake | 26 June 2026 | News
The TCS London Marathon will expand to a two-day event for its 2027 edition, with 100,000 participants taking part across Saturday 24 and Sunday 25 April. London Marathon Events has described the one-off format, dubbed “the Double”, as the largest fundraising moment in UK sport.
It is a one-year-only change. Runners on both days will follow the same route from Greenwich to Westminster, with the elite races and championship and ‘good for age’ fields split across the weekend: women leading the mass event on one day, men on the other. Full format details are to be confirmed in the coming months.
The organiser says the expanded event responds to extraordinary demand for places. A record 1.33 million people entered the ballot for the 2027 event, and spreading the marathon across two days allows the largest number of people yet to run a single London Marathon.
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More places, more charity income
For fundraisers, the significance lies in scale. The TCS London Marathon is already the world’s largest one-day annual fundraising event, with participants in 2026 raising more than £90 million for charity. London Marathon Events believes the 2027 Double could push that figure beyond £150 million for good causes, alongside an estimated £400 million in social and economic benefit to the UK. Both figures are projections rather than confirmed totals, but they signal the additional charity capacity the weekend is intended to create.
Hugh Brasher, chief executive of London Marathon Events, called the Double the organisation’s “most ambitious evolution to date” and said expanding to 100,000 runners would open the door to more people, more charities and more communities. The Mayor of London, Sadiq Khan, welcomed the plan, describing it as a chance to create the largest fundraising moment in UK sporting history while supporting the work of charities.
How places and entries will work
Everyone who has already applied for 2027 will be entered into a ballot for both the Saturday and the Sunday, with results announced in early July through a completely random draw. Participants will not be able to run in person on both days, though they will be able to complete the event in person on one day and the virtual TCS London Marathon MyWay on the other.
The organiser is also building community participation into the weekend. Every London borough along the route has been allocated extra guaranteed entries so that grassroots groups and charities can take part, and every school in London will receive two guaranteed entries for teachers or staff. All additional income generated by the Double will be distributed by the London Marathon Foundation to projects that encourage activity among children and young people across London and the UK.
The Double will close a full week of activity that includes an extended TCS London Marathon Running Show, the TCS London Marathon and Friday Night Lights 5K, and the TCS Mini London Marathon, the world’s largest one-day timed children’s event, which takes place on Friday 23 April 2027 and is expected to welcome more than 20,000 young participants.
Charities interested in places can find further detail in the organiser’s 2027 TCS London Marathon Double announcement and accompanying FAQs.
About Howard Lake
Howard Lake is consultant editor of UK Fundraising. He founded the site in 1994 and successfully sold it in 2022. As director of Giving X Ltd he is exploring growing giving on a massive scale.
He is the founder of Fundraising Camp and co-founder of GoodJobs.