Though most IT suppliers can provide a comprehensive range of hardware, software and services, there are some differences between them. For example:
IT suppliers range from small local outfits to global organisations. Even the largest suppliers can provide systems, services and consultancy to small businesses.
You may rely on your supplier for a system that's central to your business success. You need complete confidence in them. A local business, or a larger company with a local office, can be a reassuring presence.
Unless you have extensive IT expertise in-house, it's generally best to use a single supplier for all hardware, software, services and support.
If you buy from multiple suppliers, you'll have to decide which one is responsible when there's a problem - unless you have a service provider prepared to support your whole system.
The National B2B Centre