If the domain name you want for yourself is registered to another business that also has a good claim to use it, then your only option is to find another domain name. But if it is a case of passing off, then the domain law is in your favour.
Passing off is when a competitor registers a domain name that is similar to your trademark. It is a dirty practice that is not allowed by internet law. If this is the case, you can either take court action or start a dispute resolution procedure. That way you can have the domain transferred to you.
You can find out more about domain names and why having a good one is so important for your business here.
If you need any help or advice about domain names and how to set them up and register call Scott on 0333 335 9378.