The GCHQ Christmas Challenge - Archive
A brief history
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 puzzle volunteers, as a nod to our work which sees us solving the most complex of problems.
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 and colleges. However, 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.
2021
2021 marked the first GCHQ Christmas Challenge. Solve the seven puzzles, which increase in difficulty as you progress Link each answer to the glowing node on the tree that best matches the question or answer. Once complete, discover the hidden message.
2022
Our Christmas Challenge returned in 2022 with an additional twist! It once again features seven puzzles based on the seven disciplines of languages, engineering, codebreaking, analysis, maths, coding and cyber security - all key skills needed at GCHQ to help keep the country safe. Once you solve all seven puzzles, you'll need to use the design on the front of the card to assemble the answers, forming three separate what3words locations. Joining the three place names together will reveal a special festive answer.
2023
The 2023 Christmas Challenge was our toughest yet! Solve the seven puzzles and then use the design on the front of the card to help put letters into a grid at the bottom of the card. Once complete you'll reveal a seasonal hidden message.
2024
In 2024, we took it up a notch, taking puzzle-solvers on a trip around the UK on Santa's Sleigh, with the seven fiendish brainteasers joined by hidden puzzles and codes in the design of the card.
2025
The 2025 GCHQ Christmas Challenge came with a proper twist! We tasked schoolchildren up and down the UK to design the front cover of the card and hide their own codes for bonus puzzling alongside the seven brainteasers set by Chief Puzzler Colin and his puzzle team!
Download the 2025 GCHQ Christmas Challenge
Download the 2025 GCHQ Christmas Challenge solution
