If you have a business current account, the chances are it pays 0% interest. So any businesses with cash stored, even just to pay the taxman, are missing out on interest.
If you're a sole trader, you're likely to be able to save the business's cash in a personal savings account. It's best to do this, as you get the best rates. But if you've a limited company, then you'll need to use a specially designed business savings account.