OPERATION BLETCHLEY: LONDON — CRACK THE CODE. COMPLETE THE MISSION.
Step into the shoes of a WWII codebreaker this July with Operation Bletchley: London, the ultimate codebreaking challenge in support of the Army Benevolent Fund.
This summer, take on one of the UK's most innovative events, walk 50* miles (or set your own distance), crack codes, and deliver your final message before midnight on 31 July 2026. Whether you're walking solo or teaming up with friends and family, this is your chance to test your body and brain — and unlock some amazing rewards along the way!
Can you deliver your message before it’s too late?
*Option to adjust distance to suit your ability.
WHAT DO I DO?
Sign up now and you will automatically create your own event page. This is so much more than just a place for your fundraising. You will use this page to track your walks, rack up your miles, mark off your cracked codes and earn fundraising milestone badges.
EASY TRACKING
You can link your page directly with Fitbit or MapMyFitness to track your walks automatically or you can simply add your miles manually to your page. Instructions on how to do this can be found here. We recommend you do this at least 24 hours before the start of the event on 1 July .
Use any device you like, the site is set up to work on your mobile, tablet or laptop, making it easy to keep track of your challenge wherever you are.
Cover the miles of your chosen mission during July and once you have cracked all the codes successfully and deciphered the final message you must deliver it by midnight on 31 July to receive your mission accomplished status and well deserved medal.
CODES
The codes will be delivered at 10% intervals of your chosen distance. There are 3 levels of code to choose from: Junior, Codebreaker and Cypher Expert.
You can choose to solve the codes right away, or save them up for the end. You'll need to solve the first 9 codes to solve the final code.
SUBMITTING YOUR ANSWERS
You can now submit the answer to each code in your event area on your fundraising page and find out instantly if you've solved each code correctly! To submit your answers simply follow these easy steps:
1.Log in to your page and go to 'Dashboard'.
2.Click on 'Codes and Answers'.
3.Choose your level (Junior, Codebreaker or Cypher Expert).
4.Choose your code number.
5.Enter your answer! You'll find out straight away if it is correct.
DISTANCE
Your 50 miles can be completed anywhere in the world, whether is your local town, village or even if you live abroad. Whether you choose to increase or decrease your distance, you must finish before midnight on 31 July. You’ll have 10 codes to crack and once all the codes are successfully decrypted you must decipher the final message and deliver it.
If you would like to adjust the distance to suit your ability, simply change this during registration or once registered, visit the 'My Fitness Activity' tab and you will be able to adjust it here.
FITNESS
Run or walk, you can do the challenge in your own time or create a competition between your friends and family and race others to try and finish first with the added twist and codebreaking element.
TIME
The challenge runs from the 01 - 31 July and you must submit your final answer by midnight on 31 July 2026 to receive your 'Mission Accomplished' status and qualify for your medal. 
HAVE FUN
Sign up and simply have fun testing yourself mentally and physically on your codebreaking challenge.
