Your off-licence business will need at least one telephone line to contact suppliers, receive trade customers' orders and so on. It's essential to have internet access, an email address and probably a website.
The telephone company will bill you every month or quarter for the calls you have made, often plus an amount for the line rental for the next quarter.
You may decide that your business will benefit from having mobile phones as well as a land line. Mobiles could be particularly useful if you or your staff are regularly away from the shop making deliveries.
Various packages and discount structures are available to business users which can help to reduce telecommunications costs. Contact your telephone company's customer services department for details.