If you have employees, you can expense the cost of staff events (often referred to as staff entertainment).
Remember you can only expense employee entertainment. You can't expense 'business entertainment'. Business entertainment applies to anyone who is not an employee of your side business, and can include:
You will have to exclude your own cost of attending the event. You also cannot expense the cost of entertaining any attendees who are not employees. These could be clients, advisors, or potential employees.
If you regularly provide team events and other entertainment for your employees, this may become a taxable benefit to them. Only one annual staff event per year is exempt from becoming a taxable benefit in kind, so long as it costs less than £150 per head and all of your employees are invited.