There are several reasons why UK banks may refuse to work with crypto companies:

1. Regulatory concerns: Cryptocurrencies are a relatively new technology, and the regulatory framework surrounding them is still developing. Banks may be hesitant to work with crypto companies due to concerns about compliance with anti-money laundering (AML) and know-your-customer (KYC) regulations.

2. Risk management: Cryptocurrencies are associated with a high level of risk due to their volatile nature and lack of a centralized governing body. Banks may view working with crypto companies as a risky proposition that could expose them to financial and reputational risks.

3. Lack of understanding: Cryptocurrencies are a complex and technical subject, and many bank executives may not fully understand the technology and its potential applications. This lack of understanding could lead to a reluctance to work with crypto companies.

4. Negative public perception: Cryptocurrencies have been associated with criminal activity such as money laundering and terrorist financing. This negative perception could lead banks to avoid working with crypto companies to avoid any potential association with illegal activity.

It is worth noting that some UK banks are starting to work with crypto companies, as the technology becomes more widely accepted and regulated. However, there is still a long way to go before crypto companies are fully integrated into the traditional banking system.