The answer to that question is probably "Yes" but then you will say, I would say that because it is my business- so don't take my word for it you figure out if your business need a website. Before you spend any money ask yourself the following questions:

Do your customer look for your services/products on the net?
Yes! most of the average British house hold have access to internet and they would research before they part with their hard earned money. So your customer will expect to find you on the net.

Do your competitors have a website?
Imagine that a prospective client is considering hiring your business and is attempting to use the web to compare your services to the competitors. If you don't have a site, it makes you appear less established and professional. Its like not having a business card.

Are your competitors larger than you?
If your business is very small, or you're just starting out, you may want it to appear larger than it is. A well-designed and highly professional website gives the appearance that your business is large and established.

Do you want to expand your customer base?
If you want to grow your business, you will need a web site to reach clients in new areas. Suppose you've always focused on one industry, but now want to offer a new service tailored to a different industry. Your website can be easily modified to accomodate the intended audience.

Investing in website is not very expensive business now, if you go for a right company- There are company offering basic website package starting from