In the UK, should I use inquiry or enquiry?

In British English, the noun “inquiry” has been traditionally defined as a request for information in formal and legal contexts, whereas “enquiry” was used in a broader sense. However, in modern-day usage, “inquiry” is more common in both general and formal contexts, while “enquiry” is still strictly reserved for general matters.

The same distinction applies to the verb forms “enquire” and “inquire.”