Many companies have to go through a re-branding process at some point. This can be for a number of reasons such as financial or change of management or change of direction of the company. Re-branding a well-established company can be a worry as you will need to reassure your current clients that the level of service you offer will not change and entice in new ones without the power of your previous brand.
When you do a re-brand it is best to inform as many of your customers as possible prior to it happening and try and explain the impact, if any, it will have on them with regards to doing business with you. You may also want to get the local newspapers on board to do an article about it and even consider doing a re-launch event.
If the re-brand is due to a financial matter that you may not want to publicise you will have to check legally what and who you need to tell.