The TCS London Marathon is to become a two-day event for the first time in its history in 2027, allowing a record 100,000 participants to take part.
Organiser London Marathon Events (LME) announced that the one-off format change will take place on Saturday April 24 and Sunday April 25, 2027. Participants will tackle the traditional 26.2–mile route on both days stretching from Greenwich to Westminster.
The expansion aims to accommodate the growing demand for the event and further elevate its status as an international marathon brand. According to LME, the change doubles the chances of applicants securing a place through the ballot system, which closed on May 1, 2026.
All races with a Championship or award element, such as Elite, Championships and Good For Age, will be split by sex across the two days. One day will feature elite men, T53/T54 men, Championship men and Good For Age men, with the mass participation field following. The other day will host the corresponding women’s categories alongside the mass field. The general mass participation entries will not be split by sex on either day.
As a result of the main event expansion in 2027, the TCS Mini London Marathon will move to Friday April 23, 2027. The schools–based event is expected to host around 22,000 children, maintaining a similar capacity to previous years. Schools will be able to enter from January 2027.
Hugh Brasher, Event Director for London Marathon Events, said the move would create an unprecedented weekend of sport and charity. He noted that the decision follows a record–breaking number of ballot applications for the event.
LME has previously reported that a jaw-dropping 1.3 million people entered the ballot for the 2027 London Marathon, and this is the highest number of ballot applications for any marathon ever.
Securing a place for next year’s event still remains highly competitive, but the move to a two–day format changes the odds somewhat. LME does not publicly break down the number of spots reserved for the public ballot versus charity partnerships, corporate sponsors, good for age, and elite entries. Although, the odds can be broken down using overall event capacity and historic ballot trends.
If every single spot in the marathon were allocated purely via the public lottery:
- Via the original one-day format (based on 59,830 participants at the 2026 event): the chance of being selected via the ballot would be around 4.5% (roughly a 1 in 21 chance).
- Via the new two-day format (100,000 places): the chance climbs to around 7.5% (roughly a 1 in 12 chance).
Based on the assumption that around 20,000 places are actually allocated via the UK public lottery (with the remainder going to charities, sponsors, travel providers, etc):
- Via the original one-day format: the chance of being selected via the ballot would be around 1.5% (roughly a 1 in 66 chance).
- Via the new two-day format: the chance doubles to around 3% (roughly a 1 in 32 chance).
London Marathon Events is a non–profit organisation that directs its surpluses to the London Marathon Foundation, funding grassroots sport and physical activity projects across the UK.
Frequently Asked Questions (FAQs) for the 2027 TCS London Marathon
When will ballot results be announced?
Applicants will receive their ballot results in July 2026, which will also confirm which specific day they have been allocated to run.
Can participants run on both days?
No. Runners are only permitted to participate on one of the two days.
How does this affect deferred entries?
Any runner who deferred an eligible entry from the 2026 race will automatically be allocated a place on Sunday April 25, 2027.
Will the ballot reopen?
No. The ballot for the 2027 event closed on May 1, 2026, and will not be reopened.
How are charity places being managed?
Charities with existing allocations for Sunday are able to apply for additional places on Saturday. Applications for Saturday charity places are open from June 19 until 16:00 on June 25, 2026, with allocations decided by a ballot in early July.
What happens to the virtual event?
The TCS London Marathon MyWay virtual event will run across both days. Participants can choose to complete their distance on either the Saturday or the Sunday, with the timing window for each day running from 00:00:00 to 23:59:59.
Is this a permanent change?
No. The organisers have confirmed that the two–day double format is a unique, one–off arrangement specifically for the 2027 edition.
www.tcslondonmarathon.com
www.londonmarathonevents.co.uk
