Starting January 1, the UK and over 40 countries began enforcing the OECD's Cryptoasset Reporting Framework (CARF), requiring major exchanges to report users' crypto transaction data and tax residency to tax authorities. The UK is one of the initial 48 countries adopting CARF, with plans to share collected data internationally by 2027. Overall, 75 countries have committed to CARF, with the US scheduled to implement it in 2028 and commence data sharing in 2029.