Your sandwich bar will need at least one telephone line to receive customers' orders and enquiries, contact suppliers and so on. It's essential to have internet access and an email address. A website is an excellent way to advertise and promote your business. You may decide to accept customers' orders online and perhaps by text.
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 land lines. If you decide to offer a delivery service, for example, business mobile phones will be useful for keeping in contact with your drivers.
Many different internet service providers (ISPs) offer connections and email accounts. If you decide to offer wifi (wireless internet) hotspot access you will need a business grade broadband service and associated hardware and software. Shop around to find the best deal for the package of services your business requires. Think about whether your wifi access will be free to customers or charged-for (many sandwich bars and cafes provide it free to their customers). You could consider using time-limited vouchers to regulate free WiFi access.
Various packages and discount structures are available to business users which can help to reduce your telecommunications costs. Contact your telephone company's customer services department for details and to make sure that you're getting the best deal they offer.