How to do a patent search

A patent search checks whether an invention is genuinely new by looking for existing patents and published applications covering the same ground. It is the step that decides whether filing is worth the cost, and it is far cheaper than finding out during examination.

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How do you run a basic search?

1. Define the invention precisely. What it does, how it works, and what makes it different from what already exists.
2. Build a keyword list. Include technical terms, synonyms and industry phrasings. The same mechanism is often described three different ways across three patents.
3. Search the official databases. Start with the free ones. Our recommended tools cover the main options.
4. Add classification codes. Combine keywords with International Patent Classification (IPC) or Cooperative Patent Classification (CPC) codes to narrow results to the right technical field.
5. Review what you find. Look at function, structure and above all the claims, which define what each patent actually covers.
6. Record everything. Keep patent numbers, titles and links. You will need them when filing or when briefing an attorney.

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Why do classification codes matter so much?

Because keywords alone miss things. Patent drafting favours broad, unusual language, and an invention described as a "fastening assembly" will not surface in a search for "clip".

Classification codes group patents by what they do rather than what they are called, which is why professional searchers lead with them.

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What does the search not tell you?

Whether you are free to sell. A search for novelty asks whether your invention can be patented. Freedom to operate asks whether making it would infringe someone else's patent, and it is a separate exercise.

An expired patent also still counts as prior art. It can block your application even though nobody can enforce it any more.