On 22 January 2024, the United Kingdom's Communications Authority (Ofcom) published a guide with advice on how Internet of Things (IoT) and third-party equipment vendors can respond to network change. Vodafone, Three, and EE are expected to shut down their 3G networks by the end of 2024, and VMO2 is expected to shut down in 2025. There are no specific plans for mobile network operators in the UK to announce a shutdown of the 2G network after the 3G shutdown, but this will be done by 2033 at the latest, and possibly as early as 2028. All 2G and 3G devices will need to be upgraded to at least 4G at that time.
Click this link is the original Ofcom guide.