By registering a sign as a trademark, the holder receives a unique monopoly on the use of that sign for certain products and services. But this advantage for one is also a disadvantage to another, namely for those looking for a new name for their company or product. Always perform a search to check whether your trademark may be used. The internet is for this course ideal for a first rough sorting. It immediately becomes clear if the domain name is not available when there are possible competitors with the same name. However, remember that an internet search shows only a small portion of all the potential problems.
Holders of an earlier similar mark, and companies with an older trade name may also object your use. It is not just about the identical name, but also about visual, aural or conceptual similarities. Should the resemblance be too great, and the mark used for somewhat similar products and services, a company can be forced to change the name. This brings not only huge costs on (think of recovering the products from the market, new company logo / website / printing / social media), it is an unnecessary destruction of a large part of the accumulated goodwill.
Avoid this form of monetary destruction and check at the beginning of the creational process whether a name is available by performing a trademark search. There are many forms of searches possible (short quick limited checks all the way to extensive searches).