About the challenge
All you need to know about the GCHQ Christmas Challenge - our annual festive puzzling adventure
Coming soon! The 2026 GCHQ Christmas Challenge will take place on Thursday 10 December.
Puzzling minds at the ready, Chief Puzzler Colin and his ingenious team of puzzlers have been hard at work in setting you our latest festive puzzling adventure that tests all of your problem-solving skills.
Schools registration now open
Calling Teachers and Educators - we're delighted to confirm that registration for the 2026 GCHQ Christmas Challenge is now open!
Head to our Schools & Educators page for all you need to know, how to register and what to expect when it comes to taking on the Challenge in the classroom or at home.
A brief history of the GCHQ Christmas Challenge
For many years Director GCHQ has traditionally sent a Christmas card to national security colleagues and partners across the world who work alongside us every day to counter organised crime gangs, terror groups and hostile states looking to do the UK harm.
The cards have always included a brainteaser, designed by our own expert puzzle team, as a nod to our work which sees us solving the most complex of problems. These teams volunteer their time, alongside their important work, to set, solve and devise fiendish puzzles and problems that we have loved sharing with you in the form of three best-selling Puzzle Book publications.
In 2021, the card evolved and became the GCHQ Christmas Challenge.
Pitted at 11-to-18-year-olds, it aims to support greater take up of STEM subjects in schools, colleges and home-school environments.
While the puzzles are designed for students, we always encourage the wider public to take on the challenge and test themselves against friends and family, and each year hundreds of thousands of you take on our festive challenge.
That teamwork, coupled with that rich mix of minds brings the puzzles and problems to life each December.
There are no prizes, no races - even giving it a go is a success and we want you discover a love of problem-solving and testing a new part of your mind through puzzling.
Warm up for this year with our Christmas Challenge Archive
Why do we share puzzles?
GCHQ's mission is to help keep the country safe. In doing so, we face increasingly complex issues and threats every day.
In order to keep up with the ever-changing environment we work and live in, and to protect it effectively, we need to have the right mix of minds approaching every single problem that comes our way using the best methods possible.
This does not just happen. We need to adapt and innovate constantly. Through the design, creation and solving of puzzles, our teams are able to constantly develop their skills in thinking differently and discover new and inventive ways of approaching problems.
Whilst this does not mean that staff at GCHQ spend their time putting together jigsaws and filling out crosswords, it does ensure that we attract colleagues who enjoy spending their time creating and solving puzzles, and we believe that the skills that we use in setting and solving these brainteasers are the same ones we use across our mission areas, solving the toughest of problems every single day.
Puzzles are a brilliant way to hone your creative thinking skills whilst having fun, and it helps to keep us at the cutting-edge of what we do best. It is through puzzling that we are able to showcase the skills and traits that our brilliant people use in our missions in helping to keep the country safe, and hopefully inspire the next generation of analysts, engineers, codebreakers and mathematicians to spark a love of STEM alongside the classroom.
Tips for puzzle-solving
When it comes to puzzling, there are a number of key things that you can call upon to get to the right answer. Some puzzles may appear tricky at first, but once you get the hang of them, you can learn to spot patterns, think around a problem and apply your mind to finding the solution.
Teamwork
Asking for help is absolutely fine! Whether it's asking for a hint, or calling on assistance from a family member, friend or classmate - that right mix of minds could be the secret to unlocking the problem. Just like in our work, helping to keep the country safe.
Time
It's not a race. Leaving a problem and coming back to it could help you look at it differently and have that lightbulb moment. We don't expect you to complete each puzzle at the first attempt. There are no tests, no revision, no competitions, no prizes - just the satisfaction of solving puzzles.
Perseverance
Sometimes looking at something from a different angle, or taking a break and trying again can unlock a new pattern or thread to pull on. By breaking the puzzle up, spotting things that look familiar or searching for groups can help you find the route to the solution.
Schools registration
By registering your class, you'll get all of our brilliant resources to give you the best insight into our top secret world
