At the moment most of the big companies who already have trillions of pounds are not paying tax - or paying a lot less than they could be because of legal "loop holes". A loop hole is when you find a bend in a rule that lets you get around doing something.
Tax is where people pay money to the government so that they can pay for public servicies - like healthcare and schools.
Most people think that that big corporations not paying as much tax as they could is a bad thing as other small companies or just ordinary people have to pay tax - but the people/corporations that have all of the money and have more than enough are legally escaping paying tax by moving money to places where the rules make people pay less tax.
The main thing I wanted to now is what is your personal perspective on what these companies are doing and there is no right or wrong answer. Just because it is legal, does this make it the right thing to do?
My personal perspective is that this is bad because if there is almost everyone in the world having to pay tax then why don't these people who don't need anymore money escape paying tax.