It is wise to register any names you want as soon as you have decided.
Domains can be registered at any time and kept until you are ready to go ahead with your site.
If you delay registration you may lose your name to someone else!
Register your domain names
The domain name you use will depend on your product or services, your position in the market and how you will market your business in the future.
In fact you will almost certainly need more than one domain name for your site.
Now doubt you will want to register the domain of your company and trading names
quickly but domain names including product names may be just as important though for
different reasons.
As a UK business you will probably wish to have .co.uk names. We normally advise that even if you are happy you have got the name right you do register the obvious variants; they can still "point to" your original site.
Allow for potential customers not spelling the name correctly, dot com variants and hyphenated names. Apart from making it easy for customers you will also provide some defence against your competition registering a name that looks or sounds like yours!
The safest way to check for UK domain name availabilty is to visit Nominet UK. Nominet is the Internet registry for UK domain names and you will see from the website that they are not in the business of selling domains directly to the public.