It appears from your question that you don't yet have a U.K. residence visa. If you are planning to run a business in the U.K., you will need to think about this before you arrive in the U.K. It is not possible under U.K. immigration rules to switch from within the U.K. from being a visitor to having a resident permit as a businessperson. You would need to apply for a visa before travel. One option if you are planning to set up a U.K. business is the tier 1 entrepreneur program, which allows you to come to the U.K. if you can demonstrate that you are a genuine entrepreneur and will be investing no less than 200,000 pounds into a new or existing U.K. business.
