As all other financial services firms in the UK, UK-based low spread forex brokers are regulated by the Financial Conduct Authority (FCA). This is a reputable regulator with long experience in overseeing the financial sector, and traders can therefore expect that all forex brokers operating in the UK will honor their obligations.
Although the UK is home to both good and not-so-good forex brokers, many of them do offer very low spreads and otherwise advantageous trading conditions. However, it is also worth pointing out that brokers based outside of Europe may sometimes offer even better combinations of low spreads and high leverage, mainly due to new regulations introduced by the European Securities and Markets Authority (ESMA), which also applies to low spread forex brokers in the UK.