Sometimes a basic Patent Search can be sufficient for your needs. What are these needs though?
Primarily a Patent Search is carried by inventors with a new concept. Patent Searching aims to find documents that disclose something identical or very similar to the invention or concept. This is called a NOVELTY search. Should you find such a Novelty Destroying document, it is advisable to stop investing time and money into the product or service.
A (patent) document that is relevant but still technically different may be useful to argue inventive step. The technical difference should be inventive or not obvious to a person skilled in this technology. This can be subjective so try to be honest with yourself. This will save you many thousands of £/$/€.