The name of your company cannot be the same as that of another registered company. Whatever name you choose, however, Companies House requires that a limited company has at the end of its name either “Limited” or, in its abbreviated form, “Ltd” (there is no difference between the two apart from how they appear on paper).
Some words are never allowed in a company name and other words may be used only if they meet specific criteria or permissions. For example, you may not use the word "charity" without the permission of the Charity Commission. Companies House regulates the use of all sensitive words and your company will not be registered if the requirements are not met.
You can use our name search tool to check whether a company name is available. This links with a government database of registered company names to find whether the limited company name that you would like to use is available at Companies House.
For further information please read our article: What name can I use for my company?