the company pays tax on any profit made you will take dividends along with a small salary usually. The company will pay 20% tax on profits up to 300k and any divends up to about 33k i think is 10% but you get a 10% credit voucher.
You would't pay any NI that's the saving but also along with that you can not take money out of the business if its going to leave u short of your tax bill its illegal and can get you into all sorts of problems if you cant pay it at the year end